ANFS305 - Final Exam

Processing plant operations

- 10,000 birds/hr - Continuous facility via monorail - Well-planned process

Double-O cheese vats

- 50,000 pounds of milk to produce 5,000 pounds (2 ½ tons) of cheese

Spirulina

- Alternative microbial protein source - A photosynthetic blue-green algae

Yogurt cultures

- Both S. thermophilus (S.t.) and L. bulgaricus (L.b.) are needed for adequate production of acetaldehyde, acetic acid, and diacetyl - L.b. primarily adds flavor and aroma, but takes pH down to 4.0-4.4

Synbiotics

- Both probiotics + prebiotics

Smoking of meats

- Originally done to preserve the food, now primary purpose is flavor development

Yogurt

- Originally from goat or sheep milk - USA: from whole or skim cow milk

Trend - lunchtime fast fixins

• Chicken sandwiches are #1; most sandwiches remain traditional American - ham & cheese, etc.

2 typical Critical Control Points (CCPs) (MP)

• Chlorine concentration in wash/flume waters • Metal detection after bagging

Sous vide - process

• Circulating water bath allows for precise cooking • Most (if not all) bacteria destroyed • Temperature and storage time must be carefully monitored

Most heat-resistant pathogen

• Clostridium botulinum (the spores are the heat-resistant form of the bacterium)

Organic meat

• From livestock that are fed organic feed, not treated with antibiotics or growth hormones, and aren't routinely confined

Appearance factors - size

• Fruits and vegetables can be sized according to the openings they can pass through

Flavor analysis equipment

• GC (gas chromatography), GLC (gas-liquid chromatography), HPLC (high-pressure liquid chromatography), MS (mass spectrometry), GC-MS, etc.

Powdered sugars

• Machine-ground from granulated sucrose • Different grades based on particle size • ~3% corn starch to prevent caking

Beer

• Main ingredients: Water & malted barley

The brewing process

• Malt - package of enzymes and food substances for yeast • Malting process necessary to activate enzymes - Does not happen at brewery

Total quality management (TQM)

• Management system striving to continuously improve the quality of products by making small but incremental changes in a product's ingredients, manufacture, handling or storage to result in overall improvement

Wheat

• Many different varieties according to yield, resistances to weather, insects and disease

Textured vegetable protein (TVP)

• Ragged, porous granules of isolated soy protein that rehydrate quickly • Can be used to extend meat • Fat-free but absorbs fat readily

Vertical Farm

• Raising food without soil in specially constructed multistory buildings in cities • Self-contained system (total recycling)

Cocrystallized sucrose

• Rapidly agitate supersaturated sucrose to form aggregates • Second ingredient can be absorbed onto it - Can be flavorings and additives

Sous vide ("under vacuum") - general

• Raw food placed in hermetically vacuum-sealed high-barrier bags and slowly cooked in mildly hot circulating water bath • Used for meats, poultry, seafoods

Bostwick Consistometer

• Simplest and most common viscometer • Measures consistency (degree of thickness of syrups and sauces)

Still retort

• Simplest, a big batch-type pressure cooker

External cues - Health halo

• Snack foods that are labeled low-fat average only about 11% fewer calories than the regular versions

Top ingredients to avoid

• Sodium/salt, sugars, high fructose corn syrup, trans fat, saturated fats, and monosodium glutamate

Solute concentration

• Solutes in solution elevate the boiling point of water; foods high in sugars dry more slowly than foods low in solubles

Most important criterion for food

• Taste (cited by 89% of consumers) • Price (71%) • Healthfulness (64%) • Convenience (56%) • Sustainability (36%)

Boiling point

• Temperature at which a substance boils, or is converted into vapor by bubbles forming within the liquid

Smoke point

• Temperature at which smoke comes continuously from the heated oil's surface • After smoke point comes flash point

Factors affecting the choice of final temperature

• Textural changes • Enzymatic changes • Nonenzymatic chemical reactions • Microbiological changes • Costs • Ex: -18°C is well below the lowest growth temp. for pathogens (3.3°C) and spoilage microorganisms (-9.5°C)

Plasticity - another property of fats

• The ability to be molded or shaped • Influenced by the state of fat crystallization • Fats can be made more plastic by chilling and agitation which affects crystallization rate and form

Amylopectin (1/2 starch fractions)

• The branched fraction; molecules are very large in size (typically more abundant than amylose)

Winterizing

• When oil is chilled, triglycerides with high levels of saturated fatty acids and with longer-length fatty acids will tend to crystallize out of the oil • Therefore, before the final product is bottled, it is cooled and crystals are removed

Spoilage

• When there is undesirable microbial growth in a food

Prion disease - Abnormal proteins

- Capable of causing normal prion CNS proteins of host to form more abnormal proteins - Causes kuru and variant Creutzfeldt-Jakob disease in humans, and Mad Cow disease in cattle

Making of cottage cheese

- Casein of skim milk coagulated by acid at 20 to 33°C - Curd cut into cubes and heated to lower curd moisture - Washed and cooled

Creutzfeld-Jakob Disease (CJD)

- Classical CJD = Most common human prion-caused disease, >60 years old - Variant CJD (vCJD) = very rare form first emerged in UK in mid-1990s, affects late teens to early 40s

Structure & composition: Egg yolk

- Composed of concentric layers of light and dark material - Market eggs are usually infertile - Yolk is about half water and half fat; essentially all fat of egg is in the yolk - Source of vitamin A

Foods produced primarily by LAB alone

- Cultured dairy products - Fermented meats - Pickles - Sauerkraut - Olives

Sausage products

- Different sausage varieties are as diverse as different cheese varieties

Composition and nutritive value: Eggs

- Egg proteins have excellent nutritional quality - Major protein of egg white is ovalbumin - Ovomucin is present in relatively small amounts, but contributes to "globbiness" of egg white - Major proteins of yolk are lipoproteins

Commercial processing: Eggs

- Eggs highly perishable, requiring very high standards for plant sanitation and hygiene - Impossible to keep Salmonella out, so pasteurization is required (the trick = kill Salmonella while retaining functional properties of eggs) - Done by adding sodium polyphosphate to egg whites, this acidification allows slightly lower heat treatment

Egg components: Preparation & storage

- Freezing: Not done in the shell; liquid eggs or fractions are pasteurized - For yolk to avoid gelation, need 10% sugar or salt or 5% glycerin - To spray-dry egg whites, glucose must be removed

Egg quality

- Freshness counts - time - Over time: -- Egg white declines -- Water diffuses to yolk stretching membrane -- CO2 lost through shell -- Loss of moisture through the shell

Lactic acid bacteria

- GRAS bacteria commonly used to produce fermented foods - Lactic acid bacteria compete with yeasts in high sugar environments

Bifidobacterium

- Gram-positive, obligate anaerobe - Beneficial human gut organism, mostly in colon - Probiotic properties

Carbon monoxide

- Harmless to health at levels used - Gives meat a bright pink color that lasts weeks - Meat industry says CO stabilizes or sets color - Can be used to keep tuna looking fresh

Probiotic cultures

- In NA, yogurt is the preferred product for addition of probiotic cultures - The intent is to seed or elevate levels of desirable bacteria in the GI tract

Poultry

- In U.S., poultry is chicken, turkey, duck, goose - Disease always an issue in production

The environment

- Increased human population with consequent changes in land use - Animal waste management/GAP -- 130 times more animal waste than human waste

Egg substitutes

- Low-cholesterol, lower in fat and contain more PUFAs - Most contain no egg yolk, but have high concentrations of egg white - Egg yolk solids that are present are extracted with hexane (fat and cholesterol), sometimes supercritical CO2 extraction used

Mad Cow Disease and beef

- Mad Cow Disease is a chronic, degenerative disease affecting the CNS of cattle

Nitrosamines

- Many nitrosamines are known to be carcinogenic - Nitrosamines have been found in cured meat and fish products at low levels - Bacon requires 120 ppm nitrite along with 550 ppm Na ascorbate or Na erythrobate for antibotulinal activity

Meat curing

- Modifies the meat to affect preservation, flavor, color, and tenderness - Myoglobin is the primary muscle pigment

E. coli O157:H7

- More heat-sensitive than Salmonella, but survives well in freezer - More acid-tolerant than other E. coli

Prepared in a casing

- Natural casings are made from cleaned animal intestines - Most sausages made with artificial casings made from extruded tubes of regenerated collagen, cellulosic materials or plastic films

Egg structure: The shell

- Porous and allows the exchange of gases and loss of moisture from egg - Color of egg shell has no influence on flavor or quality - Dirt on shells is the most prominent cause of bacterial invasion of eggs

Egg preservation

- Proper humidity (commerical) = stored for 6 months w/ good quality - Modified atmosphere cold storage = best - Before cold storage, eggs can be dipped in hot mineral oil (called thermostabilization) - Household can store for a few weeks

Red meat & meat products

- Quality grades based on: -- Carcass maturity -- Degree of fat marbling (fat between muscle fibers) -- Muscle firmness

Pink slime

- Replace higher-fat beef with a lower-fat beef to get a desired lean ground beef at a lower cost than can be accomplished with the use of extremely lean beef cuts - Additives must be labeled due to allergenic issues

Meat structure & composition

- Skeletal muscle = hair-like muscle fibers held together by connective tissue and fat - Connective tissue = collagen and elastin - Collagen - upon heating melts to form gelatin - Elastin - resistant to heating, tough, primary constituent of ligaments

Prions

- Smaller than virus particles and highly resistant to heat, UV light, ionizing radiation, pressure and common disinfectants - Progressive debilitating neurological illness which is always fatal - Causes observable spongiform changes in brain

Eggs general facts

- Special strains of chickens bred for large-scale egg production - An average layer lays >260 eggs/yr. - About 70 billion eggs produced in U.S./yr. - 90% consumed as shell eggs, rest goes to bakery's and such

Implied benefits of probiotics

- Stabilization of intestinal environment/Resistance to enteric pathogens (diarrheal diseases) - Reduction of toxic metabolites and detrimental enzymes - Improvement of lactose intolerance to milk products/Reduction of serum cholesterol - Promotion of cell-mediated immunity - Production of nutrients and vitamins/Aid in calcium absorption - Intestinal recolonization following antibiotic treatment, chemotherapy or radiation treatment

Hot dogs

- Standard franks are made from finely ground cured beef - Emulsion pumped into great lengths of artificial casing twisted every 6 inches to form links

Prebiotics

- Stimulatory nutrients for resident probiotic cultures - Ex: Chemical compounds such as inulin, lactulose, galactooligosaccharides, fructooligosaccharides

Salmonellosis from eggs

- Today, fresh, unbroken shell eggs may contain Salmonella Enteritidis (usually associated with yolk) - About 1 in >20,000 - Refrigeration an issue - Avoid eating raw eggs and foods with such

Controlled atmosphere packaging (or modified atmosphere packaging)

- Use of CO maintains the appeal of foods without masking true spoilage; meat turns brown from exposure to oxygen long before it goes bad - Gases that are used depend upon the characteristics of the food; packaging films vary

Na nitrate (NaNO3) and Na nitrite (NaNO2)

- Used in curing formulas for meats for color stabilization, microbial inhibition and flavor development - Nitrite ion most important in preservation - Antibacterial effect

Egg as food ingredient

- Used to make emulsions (yolk contains lecithin) - Contains foaming agents (whites of eggs) - Proteins of eggs coagulate upon heating (e.g., baked custards) - Egg yolk provides color; egg white provides water - Eggs as a food (scrambled, fried, poached, hard-boiled, etc.)

Cottage cheese

- White, soft (80% moisture), unripened cheese - U.S. consumption >1 billion lbs/yr. - Bland flavor by itself, flavor additives very common for this type of cheese

Pork

- World's leading meat - >52 million in China, 8 mill in U.S.

Meats

- World's two top meat consumers are China and the U.S. (71 million tons in China vs. 35 million) - Most human societies prefer animal foods

Egg lipids

- Yolk contains lipoproteins, triglycerides, and cholesterol - Desirable goal = get cholesterol out - Feeding hens fish oil = increase in omega-3 fatty acids - Misconception = deeper-colored yolk means more vitamin A

Healthy halo (5 components)

1. Freshness 2. Avoidance (low-fat, etc.) 3. Healthy ingredients (whole wheat) 4. Natural, organic, local, close to farm 5. Ethical, sustainable, humane

Advantages of Spirulina as a protein source

1. Grows abundantly in alkaline lakes 2. Very alkaline pH ensures CO2 retained in water (decreases pathogen & M/O growth) 3. Floats (easy harvest) 4. Richest sources of plant origin protein - easily digestible 5. Vitamins such as γ-linolenic acid and vitamin B12 8. Exceptional yields per unit area 9. Minimum growth requirements 10. Safe

Wet milling of corn

1. Kernels steeped in warm water 2. Milled to pasty mass pumped to water-filled settling troughs 3. Remaining slurry passed through centrifuges to separate 4. Dried 5. Starch fraction to corn starch 6. Protein fraction to corn gluten (animal feeds) 7. Corn starch for corn syrups

Clean labels - 3 rules

1. Remove or replace food additives 2. Choose recognizable ingredients that do not sound chemical or artificial 3. Process foods using traditional techniques that are understood by consumers and not perceived as being artificial

Milling

1. Rollers break open the bran and free germ from endosperm 2. Flakes of bran and germ removed through sieves 3. Endosperm further ground into flour

Coffee bean preparation

1. Spontaneous fermentation - remove skin, pulp 2. Green beans sorted and shipped 3. Roasting creates aromatic flavor compounds, more porous, change to brown 4. CO2 formed during roasting - keeps flavor and aroma

The three steps of malting barley

1. Steeping - moisture of kernel from 10 - 44% 2. Germination step - changes due to enzymatic breakdown of starchy endosperm 3. Kilning - kernel dried to preserve enzymes produced during germination and heated to induce Malliard reaction (color, characteristic, roasted flavors)

Pasteurized foods...

Are not sterile

Glass packaging

• Chemically inert & an absolute barrier to oxygen and water vapor but heavy and breaks

Satiety

• Sense of fullness and loss of hunger • Measurement is subjective • Index has been developed

Trade standards

• Set-up voluntarily by members of an industry to assure at least minimum acceptable quality

Simple sugars

• Targeted for reduction

Earth's maximum population

~20.7 billion

Ionizing irradiation & organic foods

• "Does not use pesticides or synthetic (or sewage-based) fertilizers for plant materials and hormones and antibiotics for animals, does not allow foods derived from rDNA technology or the use of ionizing irradiation; emphasizes utilization of renewable resources as well as conservation of land and water"

Retortable pouches

• "Flexible cans", pouches designed to withstand retorting • Advantage over cans and jars include shorter retort times that produces higher quality products and saves energy costs

Trend - super snacks

• "Grab-and-go" and "sit-down-and-share" snacks during the afternoon

Measuring human preference - hedonic scale

• (For quality factors) - ranges from "dislike extremely to neutral to like extremely"

Maillard browning

• (Nonenzymatic browning) - reaction of aldehydes and amino groups of sugars and proteins favored by high temperature

Evaporated cane juice (% sucrose)

• 100% sucrose (crystals from evaporated sugarcane juice)

Snacking

• 16% skip lunch • Snacks now drive • 14% of food service

Honey

• 17% water and 82.5% carbs • FDA states can't have >8% sucrose • No HFCS allowed • Flavor depends on source of nectar

Trends in home cooking

• 20% rarely sat down together at home • 44% prepared in 30 min. or less • Less oven, more microwave, skillet, grill • 3/4 households own grills and over 1/2 use year round

Liquid/powdered meal replacements

• 2nd only to energy drinks as fastest-growing consumer packaged goods (food/beverage), but fastest growing dietary supplement (high-protein types most popular)

Cyclamates

• 30x sweeter than sucrose • Cyclamates are the Na and Ca salts of cyclohexanesulfamic acid • First big-time noncaloric sweetener; diet sodas started with cyclamates • Tastes very similar to sugar; heat-stable; features "slow onset" sweetness • Banned in 1969 - appeared to cause cancer in some animals (none in humans) • Replaced by saccharin

L-tryptophan poisonings

• 37 people died in U.S. • Changes to fermentative production process were made resulting in toxic chemical contaminants in the nutrient

Honey (% fructose)

• 50% fructose, 44% glucose, 1% sucrose

Grape juice concentrate (% fructose)

• 52% fructose, 48% glucose (from cooking down grape juice)

Molasses (% sucrose)

• 53% sucrose, 23% fructose, 21% glucose (from sugarcane refining)

Weekday dinners

• 56% of dinners made from scratch, but often pre-prepared items used for ingredients/preparation

Peanuts

• 6% water, 26% protein, 48% fat and 19% carbohydrate; both a legume and an oilseed • Used as whole nut, source of peanut oil

Apple juice concentrate (% fructose)

• 60% fructose, 27% glucose, 13% sucrose (made by cooking down apple juice)

Quick service restaurants

• 78% of industry • McDonald's #1 then subway, Starbucks, Wendy's, BK, Taco Bell, Dunkin

Corn syrup (% glucose)

• 8 to 96% glucose, 0% fructose, 0% sucrose (liquid made from cornstarch)

Agave syrup or nectar (% fructose)

• 84% fructose, 8% glucose, 8% sucrose (from Mexican Agave cactus)

Brown sugar (% sucrose)

• 97% sucrose, 1% fructose, 1% glucose (granulated white sugar mixed with a small amount of molasses)

Sublimation

• = under reduced pressure ice is converted directly to vapor without going through liquid phase. - Basis for freeze-drying

Hermetic closure

• A container that is sealed completely against the entrance of gases and vapors, as well as microorganisms, liquids, etc. • Essential for vacuum and pressure packaging • Flexible packages are rarely hermetic

Ohmic heating

• A continuous system - heating with electricity

HACCP - critical control points

• A critical control point is any point in the chain of food production from raw materials to finished product where loss of control could result in an unacceptable food safety risk • Risks are biological, chemical or physical • Used by food service and restaurants

Soybeans

• A curiosity in the U.S. until 1900, is now the single largest cash crop bringing more protein and more oil into the economy than any other single source

Food concentration

• A limited form of dehydration • Foods are often concentrated before they are dehydrated in a step-wise manner • Ex: Jellies & jams, syrup, fruit juices

Water activity (Aw)

• A measure of free or available water; bound water is unavailable for microbial growth or enzymatic activity • Pure water has Aw = 1.00 • Most packaged IMFs target an Aw = 0.85 (Staphylococcus aureus = 0.86)

What is minimally processed?

• A minimal process is the least possible treatment to achieve a purpose • Foods that have fresh-like characteristics • Products that maintain their attributes and quality similar to those of fresh products

Invert Sugar

• A mixture of glucose and fructose; it is obtained by splitting sucrose into these two components • Sweeter than sucrose and products remain more moist and less prone to cyrstallization

The carrageenans

• A plant gum (polysaccharide), it binds water to form a gel, increases viscosity, and reacts with proteins to form emulsions • Phased out by WhiteWave because of increasingly "strong" consumer reactions

Electronic nose

• A series of different sensors to measure aroma; uses vapors from sample headspace to create flavor profile analysis diagrams or plots

Blanching

• A type of pasteurization usually applied to fruits and vegetables to inactivate food enzymes

Causes of food deterioration - molds

• A.k.a fungi • When molds become macroscopic on foods, that's usually spoilage • Ubiquitous; airborne • 2 most common - Aspergillus and Penicillium

Hydroscopicity

• Ability to attract and hold water, which is characteristic of sugars to varying degrees

Fat tidbits

• According to FDA any product that contains less than 0.5 g of fat per serving may be labeled as "zero g of fat"

Insoluble fiber

• Adds bulk and can speed a food's transit time, but effect on satiety is unclear

HTST

• Advantage is that food can be heated more rapidly out of a container than in it

Aluminum metal (packaging)

• Advantages: Lightweight, resistant to atmospheric corrosion & shaped and formed easily • Disadvantages: Limited use in cans for retorted foods due to lack of structural strength

Label attractions

• After freshness, in descending order, those terms attractive to consumers: Natural, no preservatives, hormone-free, all-natural, local, USDA organic and organic

Teas vary according to...

• Age of leaf, season of plucking, and the altitude, soil and climatic conditions

Factors affecting HMT - Air

• Air velocity - the greater the velocity of the air the more water that can be carried away from the food • Humidity - the drier the air, the more water it can carry

Resistances to heat transfer dependent on

• Air velocity - the greater the velocity the greater the heat transfer • Thickness of product • Food package - different packaging materials have different degrees of resistance • Geometry/design of system

Commercially Sterile

• All pathogenic and toxin-producing organisms have been destroyed as well as organisms that can spoil under normal storage conditions • Thermophilic sporeformers survive

"Tounge map"

• All qualities of taste can be elicited from all regions of the tongue containing taste buds • No evidence of any kind of spatial segregation of sensitivities

Synthetic pesticides

• Allowed for use on organic farms include insecticidal soaps and horticultural oils for insect management; and Bordeaux mixture (copper sulfate plus lime), copper sulfate, copper hydroxide and sodium bicarbonate for managing fungi

Tonic Water

• Also contains fruit extracts and a small amount of quinine

GMO research projects for modified nutrient value & health benefits

• Altering oil composition • Soybean protein for use as meat substitutes • Increasing antioxidant content in vegies

Oxygen (O2)

• An extremely reactive element of the atmosphere • Molds and aerobic bacteria require oxygen for growth, so vacuum packaging or modified atmosphere packaging (MAP)

Bottled water

• An important food product (under FDA control) • Bottled water contains no fluoride

C. botulinum Characteristics

• An obligate anaerobe; it cannot grow when exposed to air • Cannot grow in food with a pH < 4.6; it cannot sporulate or grow in acid foods • Inhibited by salts, especially sodium nitrite as found in cured meats • Foods involved; examples: Baked potatoes, crushed garlic in a jar

Constituent orientation

• An oil-in-water emulsion dries more quickly than a water-in-oil emulsion

Secondary container

• An outer box, case or wrapper that holds & protects primary containers

Sanitary quality

• Analyses for microorganisms (bacteria, yeasts & molds) and insect fragments, filth; as well as X-rays to detect physical contaminants (e.g., glass fragments, stones, metal fragments)

Adding solutes to water - dispersions

• Anything that lowers vapor pressure raises the boiling point • Solutes (e.g., salts or sugars) reduce vapor pressure • A colligative property of water is affected by the amount of solute dissolved in water • Freezing point drops with addition of solute to water (the solvent)

Forming

• Application of pressure into specific shapes • Process is product dependent

Food dehydration

• Artificial drying of foods for preservation under controlled conditions (often down to 1 to 5% moisture) • Goal is nearly complete removal of water from foods that causes minimum or ideally no other changes in the properties of the food

Factors affecting HMT - Pressure

• As pressure is lowered, the boiling temperature decreases • As water evaporates, it cools the surface due to the latent heat of phase change • As more moisture lost, cooler the food, as food becomes drier and loses less water, surface heats up and detrimental heating occurs

Hydrostatic cooker and cooler

• As shown in the videotape on tomato processing, a continuous process

Nutrasweet

• Aspartame - used globally in over 3K products Discovered in 1965 - mixture spilled, powder on fingers, tasted sweet

Slowing things down (Refrigeration)

• At 0°C, shelf-life of perishable foods ~ <2 weeks. • At 5.5°C (realistic temp. for home refrigeration), shelf-life often <1 week. • At 22°C (room temp.) these foods may spoil in a day or less

SYSCO, #1 supplier

• Away from home • Distribution of food and related products and services to restaurants, nursing homes, hospitals, hotels, motels, schools, colleges, cruise ships, sports parks, airlines, and summer camps

Pathogens that are not spoilage agents

• Bacillus cereus • Bacillus anthracis (also known as anthrax) • Clostridium perfringens • Clostridium botulinum

Most heat-resistant organisms

• Bacillus stearothermophilus and Clostridium thermosaccharolyticum, which are nonpathogenic spoilage bacteria that also form spores

What is the difference between bacteria, viruses, and protozoa?

• Bacteria can reproduce in the food and viruses and protozoa cannot

Resistance to irradiation

• Bacterial endospores • Some vegetative types of bacteria, but these are spoilage m/o (e.g., Deinococcus radiodurans) • Viruses and enzymes • Typical sterilizing dose = 4.5 Mrad (human lethal dose = 0.6 to 1.0 Krad)

Yeast

• Bakers' yeast is Saccharomyces cerevisiae. • Used in two forms: Moist pressed cakes and dehydrated granules

Rationalization

• Believe that since they're eating something that isn't as good to the real thing, they deserve a little more

HPP and bacterial spores (General Facts)

• Bert Hite first investigated HPP as a food processing technology in the 1890s • Survival of bacterial spores exposed to >1,724 MPa (250,000 psi) for 45 min (Bassett & Macheboeuf, 1932)

Taking out & eating out

• Better economy = more eating out • Americans are more likely to take-out from a restaurant than to eat food on-site at the restaurant

Evolutionary examples - bitter

• Bitter taste can represent toxic compounds such as plant alkaloids (strychnine is quite bitter); plant alkaloids evolved as protective mechanism in plants against foraging animals

Soybean protein

• Bland flavor of soybeans encouraged development of highly flavored fermented products (soy sauce) • Tofu - processed soybeans

Culinology

• Blends culinary arts and food science

Maple Syrup

• Boiled sap from maple tree • Water content reduced to 35%

Fruits

• Botanically house the seeds • Culturally, eaten alone or as a dessert

Disintegration

• Breakdown of large food particles into smaller particles • Some cutting now done with high-pressure water jets and laser beams. • Disintegration often involves heat build-up

Trend - wake up call

• Breakfast trade is growing (although 15% skip breakfast); coffee #1 "food" consumed in morning (53% drink it every day); yogurt is fastest-growing breakfast food; 51% eat pizza for breakfast

Foods derived from rDNA technology

• Broad consensus among biologists that rDNA methods are safe • Does not result in food which is inherently less safe than that produced by conventional ones

External cues - Power of expectation

• Brownie on china > paper plate > napkin

Fat property - Melting point

• By convention, if a lipid is solid at room temperature, it is a fat; if a lipid is liquid at room temperature, it is an oil

Brewer's yeast

• CO2 production is secondary to ethanol production

Oven

• Cabinet holding a magnetron, microwaves reflected and bounce with the metal cabinet walls and metal fan

Coffee & tea

• Caffeine and related methylxanthines do affect appetite, but exact effects unclear

Composition and nutritive value of tea

• Caffeine content depends on brew method: Longer brewing time = greater caffeine • Tea contains small amounts of theobromine • Appears to have an inhibitive effect on iron absorption when consumed with a meal

Olestra™/Olean™

• Can withstand heat • A sucrose ester = a sucrose to which 6, 7, or 8 fatty acids are attached • Close to mimicking structure of triglycerides • Fat-digesting enzymes (i.e., lipases) do not breakdown Olestra

Vacuum driers

• Capable of producing highest quality dried products, but costs are higher • Reduced pressure means reduced boiling point of water means reduced application of heat

Club Soda

• Carbonated water with sodium bicarbonate and potassium carbonate added

Enzymatic browning

• Caused by a combination of polyphenol oxidase (browning enzymes) polyphenols and oxygen

Clostridium botulinum

• Causes botulism, a foodborne intoxication, not a foodborne infection • Results of botulism can be lethal, due to paralysis caused by botulinal neurotoxin • Spores are heat-resistant, comparatively vegetative cells and neurotoxin are not • Moist, low-acid canned foods are susceptible to C. botulinum if not adequately processed

Reverse osmosis

• Change of normal flow of water through the membrane by applying pressure on the solute side of the membrane in excess of osmotic pressure

Physical structure of ice cream

• Changes in physical structure are cause of common ice cream defects

CuSO4

• Chemical is produced by treating copper metal with hot concentrated sulfuric acid or its oxides with dilute sulfuric acid • Copper sulfate is most often used as a fungicide, as well as a herbicide and a pesticide - popular in grapes, melons, and berries

Nutritional quality

• Chemical or instrumental analyses for specific nutrients

Edible films/coatings: Examples

• Coating of raisins with starches to prevent moistening of packaged breakfast cereals • Coat fresh fruits and vegetables with wax to reduce moisture loss and resist growth of surface molds • All edible films must be approved by the FDA

Coffee

• Coffee plant (Coffea arabica) native to Ethiopia; Brazil is now #1 producer • Grows 6-20 ft. high

"Clean labels"

• Collate the latest research and market data to help manufacturers compose consumer-soothing ingredient lists

Munsell system

• Color can be defined or measured based on division into three components using a numerical scale (value, hue, chroma) • Color measurements can be done at high speeds

Hurdle Technology

• Combination of food processing technologies or preservative factors called hurdles

Primary container

• Comes into direct contact with food (e.g., can or jar)

Solvent extraction

• Common procedure to remove oil from cracked seeds at low temps with nontoxic fat solvent • Oil yield greater with extraction than pressing - sometimes the two processes are combined

Case hardening

• Common with foods that contain dissolved sugars and other solutes in high concentration

Sterilization

• Complete destruction of all microorganisms • Usually requires a treatment as 15 min at 121 °C (250 °F)

Tannins

• Complex mixtures of phenolic cpds • Usually colorless • Water-soluble in grape, apple, teas • Color depends on type (pH-sensitive) • Deliver astringency that influences flavor and contributes body to beverages

Plastics packaging

• Composed of very large long-chain molecules (polymers) • Thermoplasticity of plastics allows them to be formed into almost any shape

Basic parts of a refrigerator

• Compressor compresses refrigerant gas, raising the refrigerant's pressure and temp. • Refrigerant cools outside the refrigerator condensing into a liquid and flowing through expansion valve • Refrigerant moves from a high to low-pressure zone • Refrigerant expands and evaporates - evaporation absorbs heat, making it cold • Coils inside the fridge allow refrigerant to absorb heat

Evaporation

• Concentrate foods 2x-3x • Eemove water, to recover desirable food volatiles, and to remove undesirable volatiles

Changes during freezing

• Concentration effects (detrimental) - Lactose crystallization - Broken fat emulsions - Concentrated salts denature proteins • Ice crystal damage - When water freezes slowly, large ice crystals form, causes physical rupture

Dry milling of corn

• Conditioned to ~21% moisture • Passed between rotating cones • Dried to 15% and hulls removed • Brittle endosperm flattened to corn meal then corn flour

Rice

• Consumed as the intact grain minus hull, bran and germ • Milling process designed not to disintegrate the endosperm core of the seed

Corn syrups

• Contain ~75% carbohydrate and 25% water • Composition varies dependent upon manufacturing process • Corn syrup produced using acid and high temps to hydrolyze starch - Carb contant varies from 10-36% glucose and 9-20% maltose

Golden rice

• Contains transplanted genes that allow rice plants to produce kernels containing ß-carotene (vitamin A precursor) • Vitamin A-deficiency causes ~500,000 children annually in the world to become irreversibly blind; golden rice will be offered free of charge to any interested nation

Foodborne Illness

• Contamination coming from - Worker hygiene issues - Environmental contamination - Imported produce (40-50%)

Non-carbonated fruit beverages (not juices)

• Content varies tremendously; fruit juice content may range from 1.5 to 70% • Acids are normally used • Susceptible to microbial spoilage, so in addition to preservatives, pasteurization is required (by heat or microfiltration)

Rotenone and pyrethrum (organic pesticides)

• Controversial because they work by attacking the nervous system, like most conventional insecticides • Rotenone is extremely toxic to fish and can induce symptoms resembling Parkinson's disease in mammals • Pyrethrum (natural pyrethrins) is more effective against insects when used with piperonyl butoxide

Organic pesticide usage

• Controversial natural pesticides include rotenone, copper, nicotine sulfate, and pyrethrum

Synthetic pesticide issues

• Copper sulfate, Bordeaux mixture and copper hydroxide, for organic use can be more environmentally problematic than some synthetic fungicides prohibited for use in organic farming • Repeated use of copper sulfate or copper hydroxide may result in copper accumulation to toxic levels in soil

HFCS Process

• Corn starch treated with enzyme (α-amylase - removes individual glucose units) • Then treated with glucose isomerase (converts glucose to fructose) • HFCS = 42-55% fructose (rest is glucose and higher sugars)

High-velocity blast freezers

• Counter-current air flow often used - Coldest air first contacts already frozen food as it leaves freezer; this makes freezing progressive

Porosity

• Creating steam pressure within a product during drying (escaping steam tends to puff up the product); e.g., extrusion • Whipping or foaming prior to drying • Vacuum drier by rapid escape of water into the high vacuum

Nicolas Appert

• Credited with developing the technology of canning • 'Father of food science'

What caused change of heart in irradiation?

• E. coli O157:H7 'Jack-in-the-box' outbreaks of 1992-1993 in Washington state • Ground beef • Hemolytic uremic syndrome • Outraged parents: "A safe technology available to prevent, why can't it be used?"

Mechanism of bacterial inactivation

• Cytoplasmic membrane is the key site; leakage of intracellular components related to pressure-induced injury and inactivation • HPP causes denaturation of membrane proteins and membrane lipid gelation • More unsaturated membrane fatty acids, greater membrane fluidity, generally greater pressure resistance

Dating systems

• Date of manufacture (pack date) • Date the product was displayed (display date) • Sell by or pull date • Use by or expiration date

Food deterioration

• Declines in organoleptic desirability/aesthetic appeal, nutritional value, and safety (that is, declines in food quality) occur under the best of conditions

Change in pectins & acids after harvest

• Decrease in water-insoluble, increase in water-soluble Leads to gradual softening Organic acids in fruits decrease with S&R

Pasteurization - Alcoholic Beverages/Fruit Juices

• Designed to extend product shelf-life

Fitness Beverages

• Designed to prevent dehydration and give a quick energy burst during strenuous exercise • Same osmotic pressure as human blood (isotonic) for rapid absorption; for electrolyte replacement: K phosphate, NaCl, Na citrate, and KCl used • Carbohydrate content of 6 to 8% common • Low level of carbonation to avoid GI discomfort when consumed in large volumes

Fermented foods

• Desirable microbial growth • Various kinds of carbohydrate breakdown, usually acids and alcohols are produced by microbial metabolism

Insects

• Destroy ~5 to 10% of U.S. grain crop annually (~1/3 of all U.S. crops lost to insects) • Insects damage crops so that spoilage m/o are more of a problem • Some foods cannot be produced without some contamination

Fat property - Solubility

• Determines if a compound is a fat; if a compound is water-insoluble, it is a fat

Margarine

• Developed in 1869 by a French chemist, Mege-Mouries • Use of margarine and diet spreads have increased while butter use has declined • Cheaper, contain no cholesterol, have improved quality, uniformity and product types

Kellogg brothers

• Developed other grain-based vegetarian options for their guests at the spa; their coffee substitute was a hit

Hydrogenation

• Developed to change liquid vegetable oils into solid plastic shortenings (no water) and margarines • Stabilizes oils to prevent spoilage from oxidation (fat rancidity) • Unsaturated fatty acids are highly reactive

Bloom (defect - chocolate)

• Development of a mottled or gray surface on chocolate caused by heat and moisture • Probably due to fat recrystallization Proper processing and use of emulsifiers help reduce bloom

Fat substitutes

• Differ from fat replacements in usually having even fewer calories • Substitutes are a single, unique ingredient to replace fats

Flash pasteurization (HTST)

• Different temperature-time combinations can vary greatly on their damaging effect on foods • Shorter the processing time the better the organoleptic quality of the food • The higher the temperature the greater the kill rate of m/o

Direct flame sterilization

• Difficult to control

Ileal brake theory

• Digestion of fats in ileum, rather than duodenum (closest to stomach) increases satiety and reduces appetite • Slim Fast Optima™ uses more slowly digested novel lipid emulsions

Nature of water

• Dipolar (negative end and positive end) • Can form weak hydrogen bonds with other water molecules (why liquid at RT, not gas) • Liquid water is denser than ice

Radiation Direct effects (vs. m/o)

• Direct hits on DNA and other key site

Sucralose

• Discovered in 1976 • Looks like granulated sugar • 600X sweeter than sucrose • Carcinogenic • Ex: Splenda

Eggs

• Do not have identity as weight control tool • Egg breakfast had reduced energy intake for 36 hours

Organic foods

• Does not use pesticides or synthetic (or sewage-based) fertilizers for plant materials and hormones and antibiotics for animals, does not allow genetic engineering or the use of radiation, and emphasizes the utilization of renewable resources as well as conservation of land and water

Inoculated pack studies and surrogates

• Done to check effectiveness of thermal processing • A substantial population of PA 3679 is inoculated into cans of food that are then processed • After processing, the cans are stored at temperatures favorable for outgrowth of any surviving spores and checked for bulging

Mashing

• Done to make soluble the valuable portions of malt and malt adjuncts to cause breakdown of starch and proteins • At 65 to 70°C, saccharification occurs • Insoluble materials settle to bottom, the filtered liquid is called wort

Bacterial endospores

• Dormant spores show no metabolic activity • Spores represent a survival mechanism

Factors affecting HMT - Temperature

• Driving force = the temperature differential between the heating medium and the food (the greater the differential, the greater the driving force) • The hotter the air surrounding the food, the more moisture it will hold before becoming saturated

Dehydration rule of thumb

• Drying processes that employ high temperatures for short times do less damage to food than drying processes using lower temperatures for longer times

Vanilla

• Fermented and dried seedpods of several species of orchids

Cooked foods

• Easier to digest and more nutritious than raw; also true for plant materials • The essential step that allowed early humans to develop big brains characteristic • Softer, richer source of energy

Living situations affecting eating

• Eating alone = more likely to replace frozen with fresh

Edible films/coatings

• Edible films can protect food materials from loss of volatiles or reaction with other food ingredients by encapsulation in protective edible materials

Parenchyma cells

• Edible portion of F&V (nonwoody) • Cell wall is cellulosic (dietary fiber) • Cemented together by pectins and polysaccharides

Functions of emulsifiers

• Egg yolk = a good natural emulsifier • Disperse fat globules throughout ice cream mix • Prevent formation of butter granules • Improve whipping properties to reach desired overrun • Further make ice cream dry and stiff

Colloidal systems in foods (5)

• Emulsion - liquid dispersed in a liquid (e.g., salad dressing). • Gel - liquid dispersed in a solid (e.g., baked custard) • Sol - solid dispersed in a liquid (e.g., gravy) • Foam - gas dispersed in a liquid (e.g., egg white foam) • Suspensoid - gas dispersed in a solid (e.g., whipped gelatin)

Energy conservation

• Energy costs a significant part of the cost of producing foods, therefore equipment design and overall process design are engineered with optimization of energy use in mind

Biochemical regulators that decrease appetite

• Enterostatin and insulin in pancreas • Cholecystokinin, glucagon-like peptide 1, and peptide YY in the small intestine

Degradative enzymes

• Enzymes probably the second greatest cause for food spoilage • Many of the same principles for food preservation apply for enzymes as for m/o • Some food enzymes may be more resistant than m/o, as in food irradiation

Farming is 'high tech'

• Equipment guided by satellites, fertilizers are rationed by sensors and software to increase yields, improve profitability, and minimize nutrient runoff into waterways

The nose & mouth

• Estimated 80% of flavor is derived from odor • Taste buds also on front roof and back roof of mouth • Primary tastes: Sweet, sour, salty, bitter and umami (MSG - savory-like)

Heat & cold (of storage)

• Excessive heat denatures proteins, breaks emulsions, dries out foods, and destroys vitamins • Uncontrolled cold will damage fruits & vegetables if allowed to freeze resulting in discoloration and texture changes • Freezing milk will break its emulsion and casein will curdle

Moisture

• Excessive moisture can lead to undesirable microbial growth • Surface moisture from high relative humidity can cause lumping, caking, browning, crystallization, and stickiness • High moisture-barrier films can trap moisture from respiration and transpiration in fruits & vegetables

Controlling rancidity

• Exclude light, moisture, and air (oxygen) • Keep refrigerated • Add antioxidants to prevent rancidity • Avoid reusing old cooking fat

Foods to fool a stomach

• Expanding food volume with air and water • Extruded breakfast cereals could be processed for greater expansion and lower bulk density; same for bakery products

Food irradiation (Background and Exceptions)

• Exposed to ionizing irradiation to extend the shelf-life of some products, and reduce risk of foodborne illness • Continuous food processing technique • Dairy products and eggs cannot be irradiated because it causes undesirable changes in flavor or texture (issues with fats)

Allergenicity

• FDA assessment based on - source of gene(s) - amino acid sequence homology of newly introduced protein(s) to known allergens - immunochemical reactivity of protein(s) - physicochemical properties of introduced protein (e.g., digestive stability)

The fat of chocolate

• FDA has standard of identities for chocolate products related to fat content • Must be carefully tempered after conching to ensure desirable textures occur • Fat of chocolate plays key role in eating quality

Good manufacturing practices (GMPs)

• FDA requires GMPs be followed to help assure food safety and wholesomeness • Specific safe regulations for low-acid canned foods (foods thermally processed, pH >4.6, water activity >0.85, and not stored under refrigeration) • Regulations for acidified foods

Rate of freezing

• Fast freezing is required for high quality • The smaller the size of the ice crystal, the better • Fast freezing minimizes concentration effects by decreasing the time concentrated solutes are in contact with food tissues

Chlorophylls

• Fat-soluble and in nature bound to proteins • Pheophytin formed with resultant color change to olive green or brown

Carotenoids

• Fat-soluble and range from yellow to orange to red • Orange carotenes (carrot), Red lycopene (tomato), Yellow-Orange xanthophyll (corn) and crocetin (saffron)

Yogurt

• Favorite at-home snack, followed by bars, cheese, gelatin, doughnuts, fruit juice, puddings, salted nuts • Greek-style currently holds 35% of yogurt market

Factors affecting past food safety perceptions

• Fear of the unknown; apprehension of what is not understood; educational issues • Lack of visible effects • Effectiveness of anti-biotech and anti-globalization websites

Colloidal dispersions

• Features large solute molecules that are too big to form true solutions; important in food systems • Often unstable to temperature and pH extremes - Ex: curdled milk

Table Sugar

• Fermentable by yeasts and binds water to lower available moisture • Produced from sugar cane (~⅔) and sugar beets (~⅓)

Flours/Starch

• Finer fractions - whiter in color, better in bread-making but lower in vitamin and mineral content • Protein-to-starch ratio is dependent upon variety of wheat • Starch consists of 2 fractions - difference is source of starch

Saccharin

• First synthesized in 1878, used in 1901 • 300-700 times more sweet than sucrose • Stable under extreme processing conditions; cheap and easy to produce • Cyclamates though safer than saccharin at one time (and now again?) • "Determined to cause cancer in lab animals"

Anthocyanins

• Flavonoids • Water-soluble present in F&V juices • Purple, blue, red pigments of berries (antioxidant properties) • Color depends on pH

Big gainers in milk

• Flavored/chocolate milk, high-protein milk & DHA/omega-3 milk

Turbomilling

• Flour from milling further processed to separate flour into higher protein or higher starch fractions using high-speed turbo grinders • Enables separation of flour into fractions that can be blended in any ratio allowing custom-blended flours

Optics (color and gloss)

• Food color helps determine quality, ripeness and spoilage

Aseptic packaging

• Food commercially sterilized outside of containers (usually continuously) and then placed in previously sterilized containers • Packaging containers normally utilize papers and plastic materials than are sterilized, formed, filled and sealed in a continuous operation • Sterilized using hydrogen peroxide in combination with heated air or UV light

Packaging

• Food containers • To protect food, to sell food, etc. • Wide range of packaging materials • Packaging is automated

Enzymes

• Food enzymes continue to function after death of animal or plant • Some activities can be accelerated following death • Can be controlled by refrigeration or blanching

Flavor compounds

• Food flavor compounds in various concentrations and ratios • Must be water-soluble in order to taste • Tastes also vary among people genetically • Taste buds can detect more than one basic taste

Individual quick frozen (IQF)

• Food frozen individually, usually with fluidized bed freezing, clusters are disaggregated, and food packaged under cold air, such as shrimp or peas

Minimizing freezer burn

• Food is prechilled (with high-humidity air at ~-4°C) so partially frozen food undergoes minimum moisture loss; then prechilled food is quickly finish-frozen • Packaged frozen foods minimize freezer burn

Nutraceutical or functional food

• Food that may provide health-promoting qualities beyond just the nutrients it provides • Most purchased functional food = yogurts

In a piece of drying food

• Food will lose moisture from its surface • Gradually a thick, dried layer develops confining moisture to the center • From the center, a moisture gradient develops • Drying ceases when water lost = water picked up

Sensory issues related to HPP

• Foods decrease in volume as a function of the imposed pressure; up to a 15% reduction in volume and return to its original volume with pressure release • HPP can cause changes in structurally fragile foods, such as strawberries and lettuce; cell serum loss

Alternative Retail Formats for Fresh Cut

• Foodservice • Retail grocery • Vending • Food trucks

Ultracentrifuges

• For finely separating fluid foods, such as purees • Time saver - minutes to extract oil from a vegetable puree • Clean division of layers • Powerfully aromatic liquid layers, oil/fat extraction, removal of solid particles

Shortenings and frying oils

• For frying, shortenings with short plastic ranges and low melting points preferred - Minimize greasiness from unmelted fat in the mouth when fried foods eaten • Neutral flavor, high enough smoke point for use in frying

Research standards

• For internal use by a company to maintain a competitive edge

Taste panel types - trained people

• For specific products (e.g., butter and cheese).

Functions of stabilizers

• Form gels with water in mix to improve body and texture • Give a drier product that does not melt rapidly or leak water • Prevent large ice crystals from forming during freezing (large ice crystals = coarse texture)

Conventional milling

• Format is basically a progressive series of disintegrations followed by sievings (separations)

Form-fill-seal packaging

• Formed in-line by assembly from roll stock or flat blanks just ahead of the filling operation in the food-handling line • Very efficient process, especially with flexible containers • Flexible materials (in form of roll stock) adapt well to high-speed manipulations and variations in size and form

Extrusion

• Formulated dough or mash is extruded through a small opening under high pressure with heat

Cold or nonthermal plasma

• Fourth state of matter: Sending an electrical current through a gas (e.g., air) to ionize it (create a plasma field and reactive oxygen species) • Plasma dissipates immediately when electricity turned-off • Surface decontamination of food products and packaging materials. • Inactivation mechanism: Damage to cell membrane and wall of microorganism

Binding of water

• Free water, "water less loosely bound", water-forming colloidal gels, and chemically bound water (i.e., hydrates)

Cold preservation and processing

• Freezing and refrigeration among oldest methods • Mechanical ammonia refrigeration systems - 1875 • Clarence Birdseye pioneered work in the production of frozen foods (1920s)

Freezing point - reminder

• Freezing point is a colligative property - a property which depends only on the number of particles present • The greater the number of solute particles dissolved in water, the lower its freezing point (and the higher its boiling point)

Supercritical CO2 extraction

• Gas form under pressure to extract caffeine from coffee • CO2 is nontoxic, can be made highly specific, process occurs under low temps so less flavor loss

Molds compared to bacteria

• Generally grow better at: - More acidic - Drier Higher salt concentrations Lower temperatures (in refrigerated foods) • Molds require oxygen for growth; vacuum packaging prevents mold growth

Nonthermal plasma

• Gliding arc system for produce testing • Using a treatment chamber (1 x 1 x 2 cm), applied directly into the food product • Equipment varies; different electrodes needed for different applications/products so plasma reaches all microorganisms of product

Aluminum foil

• Good barrier to oxygen and water vapor, but foil is very fragile • Often coated with enamel to avoid undesirable color & flavor reactions depending on the specific food

Resistances (composition of product)

• Greater conductivity = greater cooling and freezing rates • Thermal conductivity of food increases rapidly going from unfrozen to frozen state • High levels of fat or entrapped air reduce the freezing rate

Rules of thumb for freezing rates (faster when...)

• Greater the temperature difference between food and refrigerant; • Thinner the food piece; • Greater the heat transfer rate of the packaging material; • Greater the velocity of refrigerated air or circulating refrigerant; • More intimate the contact between food and cooling medium; • Greater the heat capacity of the refrigerant

Storage and staling (fresh is best - coffee)

• Ground coffee has greater surface area → cause oxidative fat rancidity • Flavor problem appears due to loss of volatile flavor compounds and exposure to high relative humidity • Brewed coffee stales due to oxidative fat rancidity and volatiles flavor loss - heat accelerates

Tertiary container

• Group several secondary cartons together into pallet loads or shipping units

Materials handling

• Harvesting and transportation while maintaining product quality to and in the processing plant - Low temperature storage ("the cold chain") - "Field heat" - Care of livestock, fragile products (e.g., eggs) and spices - Low humidity storage

Basics of pressure cooking

• Has limited headspace, so an increase in steam = increase in pressure, more heat needed to overcome surface pressure = a higher boiling point

Colloidal systems

• Have a continuous phase (major component) and a discontinuous phase (dispersed phase, the minor component)

Causes of food deterioration - microorganisms

• Healthy living tissue is usually sterile, hence the presence of spoilage organisms is mostly the result of contamination • Bacterial endospores are the most difficult microbial form to inactivate • Heat and moisture will increase growth and activities of m/o

Bacterial endospores extreme resistance to:

• Heat • pH extremes • Chemical disinfectants • Pressure • Drying • Irradiation (UV, X-ray, etc.)

Prosciutto ham

• Heat as a post-packaging control method leads to off-flavors and soft textures that are unacceptable • HPP post-packaging control method developed for prosciutto vs. Listeria monocytogenes • HPP product is not sterile; product is refrigerated • Throughput volume for HPP is somewhat limited

Cooling

• Heat exchanger can work to remove heat • Commercial blast freezers reach -26 °C • Liquid nitrogen is -196 °C

Ohmic: Alternating electric current

• Heat generated when passed through a conducting solution (i.e., water) • Low-frequency AC of 50 to 60 MHz applied with special electrodes • Food passes continuously between several sets of these electrodes • Continuous heat exchangers used to cool food quickly

Conduction

• Heat moves from one (solid) particle to another by contact

Microwaves vs. conventional heating

• Heat source causes food molecules to react largely from the surface inward, so that a temperature gradient is formed • Microwaves penetrate 1 to 2 inches; in this area heat is generated quickly and relatively uniformly • There is no surface browning; there is lack of intense heat on the exterior of foods

Control of microorganisms

• Heat, Cold, Drying, Acid, Sugar, Smoke, Atmospheric composition, Chemicals, Radiation, Pressure

Convection

• Heating in a can takes far less time due to mixing of hot fluid (mixing promoted mechanically by can movement)

Microwaving

• Heating with low-energy radiation • Electromagnetic waves of radiant energy, differing from light and radio waves only in wavelength and frequency • FCC-approved frequencies are 2450 and 915 MHz for food use

Creamy notes - misnomers

• Heavy cream is lighter in weight than light cream. Heavy cream is 36 to 40% fat while light whipping cream is 18 to 30% fat • Half-and-half: A mixture of half milk and half cream (10-12% milkfat)

Dietary fiber

• Helps maintain high levels of cholecystokinin after eating • Cholecystokinin increases fullness and eases hunger and desire to eat

Margarines: Composition

• High in PUFAs are usually soft because they contain more oil that has not been hydrogenated • Reduced-calorie do not meet margarine standard ("corn oil spread") - Less fat more water thus requires a stronger emulsification system and contains more air

Hard wheat

• High in protein, yields a stronger flour, forms a more elastic dough for bread-making

Senescence

• Quality decline in stored respiring F&V resulting from enzymatic activity

Composition of F&V

• High in water (>70-85%), Low protein (<3.5%), Low fat (<0.5%) • Digestible carbs largely sugars and starches • Indigestible cellulosic and pectic provide fiber

Pulsed electric fields (PEF)

• High voltage pulses (20-80 kV) electricity between electrodes to treat fluid foods. • A continuous preservative process: PEF-treated food is packaged aseptically and refrigerated. • Juices (esp. orange & apple), milk, yogurt, soups and liquid eggs. • Essentially ohmic heating without the heat

Reaching the boiling point

• Higher the temperature, the more energy molecules possess • Easier to overcome intermolecular forces holding them in a liquid

Charles F. Hires Root Beer

• His mix of herbs and roots not only made good root beer, but also dissolved more readily in water • Began bottling in 1893 • Nationally advertised in magazines

Sugars

• Honey was first sweetener • Sugars in dry form are ~100% carbohydrate, so foods high in sugars have low nutrient density • Levels of sweetness and solubilities vary

Hydrogenation process

• Hydrogen gas bubbled in a heated reactor through oil w/ nickel catalyst • Unsaturated double bonds converted into saturated bonds (MP increases) • Blends of fats are often done

Trans fats

• Hydrogenated oils used as a replacement for saturated fats • Moderate consumption of trans fats may have no significant effect • Butter, milk, beef tallow, lard contain small amounts (2-5%)

Chemical reactions of sugar

• Hydrolysis = glucose + fructose • Degradation = opening of ring structure as result of cooking; leads to further breakdown • Caramelization = sugar crystals melt at 170 °C • Maillard reaction involves caramelization

Intermediate moisture foods (IMF)

• IMF contain 20 to 50% moisture by weight • Do not require refrigeration because water largely unavailable for microbial growth

Condensation & excessive drying

• If non-respiring foods in a moisture-barrier package can give up moisture, changing the relative humidity of the package headspace and with a drop of temperature, condensation in the package occurs • Excessive drying leads to undesirable texture changes and appearance

Meat analogs

• Imitation meat proteins processed from soy protein into numerous forms resembling meats, such as sausage, bacon, etc. • Fortified with vitamins and methionine • Useful for vegetarians, less or no fat, but high in sodium

Dr. John Harvey Kellogg

• In 1887, developed granola from oats, wheat, and corn meal

Flavor focus

• In descending order, greatest interest in savory, spicy, smoky/tangy, sour and bitter flavors in foods • Consumers prefer hot or spicy

Corn

• In harvested wet form, consumed as a vegetable • Popcorn variety is dried, moisture in center explodes kernel when heat

Natural pH amendments

• Include lime and sulfur, and iron sulfate, aluminum sulfate, magnesium sulfate, and soluble boron products are allowed in organic farming

Organic tidbits

• Inconclusive whether the nutritive value between organically and conventionally produced foods is different • Water and salt cannot be organic • "Natural," "hormone-free," and "free range" are not regulated by the USDA; they can be used without certification, and may not be truthful statements • Can be labeled as "Made with organic ingredients" if 70% by weight of ingredients are organic

Air (Ice Cream)

• Incorporated air necessary to prevent ice cream from becoming too dense, too hard and too cold in the mouth

Overrun

• Increase in volume caused by whipping air into the mix during the freezing process (normally 70 to 100%)

Porous foods (disadvantages)

• Increased bulk • Shorter storage ability due to increase surface exposure to air and light

Soluble fiber

• Increases viscosity of intestinal contents slowing digestion that may decrease hunger

Product composition items (chocolate)

• Instant cocoa mixes contain sugar, flavorings, emulsifiers • Cocoa contains ~11% starch and chocolate ~8% • Much more theobromine than caffeine found in cocoa and chocolate

Market forms (Tea)

• Instant tea (iced) commonly contain sugar with citric acid, maltodextrins and flavorings (lemon) • Herbal teas contain dried leaves of various plants (no caffeine)

Texture

• Instron™ used to measure these forces • Chewing is a combination of forces • Texture of a food does not remain constant • Mouthfeel a key component of acceptance of a food • Change in water content plays a major role in the texture of a food

Air convection driers

• Insulated enclosure with means of circulating hot air and means of heating this air

Chopped specialty onions

• Intended refrigerated shelf-life of 45 days, but has demonstrated 90 days of storage without detrimental quality changes • HPP chopped onions have a "sweeter taste that isn't bitter, with a fresher, crunchier texture"

High-intensity pulsed light

• Intense and short-duration pulses (at least one) of broad-spectrum "white light" (wavelengths from UV to near IR, 170 to 2600 nm). • Surfaces of packaging materials and other surfaces (such as produce) to reduce/eliminate need for chemical disinfectants/preservatives. • Lethality of light pulses differ at different wavelengths (UV light of 200-320 nm most antimicrobial)

Munsell system - chroma

• Intensity or strength of the color

Oolong tea

• Intermediate between black and green • 'Fermentation' period short so that color and flavor are not as intense as black tea

Freezing by direct immersion

• Intimate contact and effective heat transfer • Minimum contact with air • High-speed freezing for high quality

Dr. James C. Jackson

• Invented granula in 1863 - dense brown nuggets that had to be soaked overnight to be chewable

Separations

• Involves solids, liquids and gases. • Hand sorting and grading still very common (e.g., fruits & vegetables)

Ionizing radiations

• Irradiated foods are not radioactive • Gamma rays and X-rays do not heat up food • Gamma rays produced by 60Co and 137Cs

Limiting indirect effects (Radiation)

• Irradiation in the frozen state limits undesirable reactions by hindering free radical diffusion • Irradiation in a vacuum (or inert atmosphere) limits oxygen's role in producing hydrogen peroxide • Addition of free radical scavengers, such as ascorbic acid

Environment for taste panels

• Isolation of tasters to avoid influence by observing other tasters and to avoid distractions • Tasters unable to see how food was prepared or what its specific identity is

Seltzer Water

• Just carbonated water

Organic food safety

• Key item: Good agricultural practices (GAPs) • Greater reliance on use of animal manure as fertilizer; issues of zoonotic diseases

Conching

• Key step in chocolate making • ~ 24 h of mixing • Lose ½ to ¾ of all volatiles • Noticeable change in odor

Ice cream

• Known in England in early 1700s • Currently >1 billion pounds of ice cream consumed annually in U.S. • 38.4% total solids and 61.6% water • Most expensive major ingredient of is milk fat

Kraft - clean labeling

• Kraft is removing artificial sorbic acid from its most popular Singles cheese product variety

Principle requirements of commercial refrigerated storage

• Large volumes require sufficient refrigeration and insulation to maintain ± 1°C • Number of doors and factors generating heat are important • Different fruits and vegetables generate different levels of heat • Air doors

Valuable volatiles in tea

• Largely responsible for flavor and aroma • Aroma complex made up of hundreds to thousands of flavor that exist in trace amounts • Many aromatic compounds do not exist in fresh tea leaves • Flavor and aroma depends on wide variety of combos of compounds

Flavor factors

• Largely subjective; very difficult to measure and very complex • Good taste: A wide divergence of opinion; it is subjective • Color and texture influence flavor • Greater color intensity = greater flavor

Organic food general facts

• Largest organic market is fresh produce • Grocery / supermarket is the largest channel

Cold Spot

• Last to reach final heating temperature

Latent heats of water

• Latent heat of fusion = energy required to convert ice to water at 0°C (for 1 g = 80 cal) • Latent heat of vaporization = energy required to convert water to vapor (for 1 g = 540 cal)

Black tea

• Leaves are withered and rolled to break tissues • Release juices held to undergo oxidative changes

Green tea

• Leaves first steamed to inactivate enzymes, then rolled and dried

Wheat flakes

• Left out boiled wheat sent through rollers and roasted • Called granose and then became corn flakes

Maltodextrins

• Less hydrolyzed to glucose than corn syrup solids therefore less sweet with bland flavor but contributes to chewiness, binding properties, and viscosity to candy

Munsell system - value

• Lightness or darkness of the color

Volatiles in tea (examples)

• Linalool and linalool oxide are responsible for sweetness; geraniol and phenylacetaldehyde are responsible for floral aromas; nerolidol, benzaldehyde, methyl salicylate, and phenyl ethanol are responsible for fruity flavors; and trans-2-hexenal, n-hexanal, cis-3-hexenol, and b-ionone are responsible for a tea's fresh flavor

Lipids

• Lipids may be most energy-dense macronutrients, but not the most satiating • Fats may retard satiety signals, but delay stomach emptying (thus sustaining feelings of fullness)

Food prep techniques

• Liquid nitrogen chilling/freezing, braising, sous vide, smoking, oil-poaching/confit, grilling, curing, pickling, and searing/sautéing

Agglomeration

• Longer residence time in spray drier results in lower moisture particles that grow in size (form clusters)

Minimally Processed Fruits & Vegetables

• MP includes all operations that must be carried out to keep the food as a living tissue • Must try to preserve Color and Appearance

Bulking Agents

• Many high-intensity non-nutritive sweeteners, but all used at far lower levels than sucrose • Macronutrient substitutes needed when taking the sugar out in any product. • Bulking agents also used with fat-free products • Bulking agents include cellulose, maltodextrins, soy fiber, and polydextrose

Predictive Microbiology

• Mathematical modeling to describe presence/absence, growth, survival, inactivation responses of microorganisms, growth opportunities, toxin production • Assess effects of processing, product composition, storage conditions • Knowledge base software

Phytoestrogens

• May help with post-menopausal hot flashes and prevent osteoporosis

Salad dressings

• Mayonnaise - at least 65% oil (most contain 80%) • Flavor dependent upon vinegar and seasonings • Imitation mayo contains more water than oil and vegetable gum to increase viscosity

Reflected color

• Measured by comparison with defined color chips

Textural factors

• Measured by resistance to force - Squeezing (compression) - Shear (as one part of food slides past the other) - Cutting - Tensile strength (resistance to pulling apart)

Spectrophotometer

• Measures color and transparency/cloudiness

PEF

• Mechanism of inactivation: Disrupts cell membranes (i.e., electroporation) • Issues concerning microbial inactivation: Spores, air bubbles, particulate matter • Gram-positive bacteria more resistant than gram-negative bacteria • For process optimization: To minimize nonuniformity in treated food

Aspartame

• Methyl ester of aspartate and phenylalanine • 180 to 200 times sweeter than sucrose • No bitter aftertaste but not stable to heat • Insignificant caloric value • People with PKU (phenylketonuria) should never use aspartame • Ex: Equal

Energy Drinks

• Methylxanthines (esp. caffeine), B vitamins and herbs. Also usually guarana (high caffeine content) and taurine • The average 8-fluid-ounce energy drink has about 80 mg of caffeine

Major causes of food deterioration

• Microorganisms (bacteria, yeast, molds) • Sources = food itself, water, soil, air, food equipment

Loss factor

• Microwave energy lost in passing through materials or being entirely absorbed by materials

Heat generation factors

• Microwaves lose energy in the form of heat as they penetrate, therefore the more heat produced the shorter the distance microwaves can penetrate • 2450-MHz microwaves and 915-MHz microwaves will penetrate to different depths dependent upon the composition of the food • Moisture content is a factor affecting penetration

Microwave physics

• Microwaves travel in straight lines, but are reflected by metals • Pass through air and most glass, paper and plastics • Highly lossy materials are heated rapidly; they absorb microwaves

Specific functions of ingredients (ice cream)

• Milk fat = rich flavor, smooth texture & body (primary calorie source) • Milk solids nonfat = flavor, body & texture • Sugar = sweetness & lowers freezing point of mix so ice cream does not freeze solid

Mellorine

• Milk fat replaced with another fat (an imitation ice cream)

Homogenization (example of disintegration)

• Milk processing - to prevent fat separation • Disruption causes denaturation of milk proteins that surround smaller, more numerous fat droplets, stabilizing them

Invisible processing (nonthermally)

• Minimally processed: Processed foods with raw, fresh-like quality; usually chilled (minimally processed fruits & vegetables have ~ 21-d shelf-life; minimum shelf-life of 4 to 7 d)

Predicting shelf-life

• Models for predicting shelf-life are particularly useful for new products without a distribution history • Done by computer modeling

Controlled atmosphere (CA) storage

• Modification of storage or packaging atmosphere usually by vacuum or addition of N2 or CO2 (either way O2 usually reduced). • CA systems typically control temperature, humidity, and gas levels in order to minimize further ripening and spoilage of fruits and vegetables • Low temps, high humidity, low O2 levels, and high CO2 levels are the most commonly used techniques. To be cost efficient, it must be done with specialized equipment in an airtight storage enclosure

Increasing monoglycerides and diglycerides in fats

• Monoglyceride (glycerol ester containing one fatty acid), diglyceride (2) • Use inert gas or vacuum to prevent oxidation • Glycerol esters are partially charged and serve as excellent emulsifiers

Measuring human preference - triangle test

• Most common - in three samples, selecting the sample that differs from two others

Caffeine

• Most commonly consumed drugs • Tea = 2%, coffee = 1% but coffee has 2x more caffeine in a cup bc more completely extracted

Spray driers

• Most important type of drier; produces more dehydrated foods than all other kinds of driers combined • Continuous process

Alimentary pastes (noodles & pasta products)

• Mostly milled wheat and water in 100:30 ratio • Usually hard durham wheat is used which is milled to coarse particles known as semolina • Often extruded and oven-dried to 12% moisture

Consumer demand for more natural foods (colors)

• Naturally derived coloring options • Color additive imparts color to a food • Synthetic colors have a bad image

Microbial Concerns? (MP)

• Naturally occurring microbial ecology • Fruits and Vegetables are not sterile • Modified atmosphere package environment • Spoilage bacteria • Pathogens

Porous foods (advantages)

• Quick solubility/reconstitution • Greater volume appearance

GMO - FDA

• Newly introduced foods produced through conventional breeding are not required to undergo safety assessment • FDA requires label information that pertains to changes in the food composition or safe use, not the breeding methods

Botulism issues

• No indicator organisms nor quality tests available for botulinogenic food • Low TPC or low coliform counts do not guarantee anything • Botulinogenic foods not necessarily putrid • Must rely on commercial sterilization or complete inhibition of toxin production

Parevine

• No milk fat and no milk solids (imitation ice cream)

Advantages to hydroponics & aeroponics

• No soil is needed • System water reused (lower $) • Possible to control nutrition levels • No nutrition pollution • Stable, high yields • Easier to control pests and diseases

Ready-to-eat (RTE) meals

• Non-frozen, refrigerated RTE meals • Everything (except tortilla in fajita ex) is pressure-processed • Superior taste as compared to thermally processed product

Wild rice

• Not directly related to Asian rice • Four species of grasses, not a rice

HFCS acting alone?

• Not pure fructose (55% but can be less) • Table sugar is 50% fructose

Satiety manipulation as means to control obesity

• Numerous studies have shown link between skipping breakfast and obesity in children and adolescents

Brown sugars

• Obtained from cane sugar during the late stages of refining • Clumps of sucrose crystals coated with a film of molasses

Celiac disease

• Occurs in genetically predisposed people where the ingestion of gluten leads to damage in the small intestine • Leads to damage of the villi so that nutrients cannot be absorbed properly into the body • Gluten found in wheat, rye and barley

Cleaning

• Often required for simple removal of dirt and debris • Water treatment (e.g., for soft drinks) • Cleaning/sanitation of food contact surfaces

Polydextrose

• Often used with nonnutritive sweeteners in frozen desserts, puddings, baked goods, frostings and candies • Provides ~25% of the calories of sucrose, therefore when used with a nonnutritive sweetener, can reduce caloric content by >50% • Litesse = commercial polydextrose

Freezing-in-air methods

• Oldest (circa 1860) and least expensive equipment • Food placed in cold, insulated room usually of -23 to -30°C • Air circulation is mild (i.e., slow convection current)

Pumping

• One of most common operations in the food industry • Many kinds - depends on nature of food • Usually made of stainless steel

Drum or roller driers

• One of the least expensive methods of dehydration • Foods usually have a more cooked character than foods dried by other methods

Blast-air freezing

• Operates at -30 to -45°C with forced cold air velocities of 2,000 to 3,000 ft/min

Coffee composition

• Organic acids • Volatile substances • Bitter substances

Fertilizers & soil amendments

• Organic farmers also use animal manure and certain processed fertilizers such as seed meal and various mineral powders such as rock phosphate and greensand (potash) which provides potassium

Organic food cost

• Organic foods tend to cost more than conventional foods because of the larger demands placed on the producer, who needs to follow stricter standards growing, processing, and distributing the product than conventional producers (also greater crop losses); also - yields lower

High-intensity nonnutritive sweeteners

• Original desire for these products sparked by goal to reduce calories and tooth decay

What are hominy grits?

• Originally one used lye to make hominy grits • Protocol: Soak corn kernels in weak solutions of lye • Lime can also be used

Multilaminate

• Outer layer is polyester film for resistance, strength, printability; middle layer is aluminum foil for barrier properties; inner layer is polypropylene providing heat-seal integrity

Hot pack or hot fill (acid foods)

• Packing of previously pasteurized or sterilized foods while hot into clean but not necessarily sterile containers • Most effective with acid foods (pH <4.6) • A substantial number of fruit products have a pH of <3.7 • Use of a retort not necessary; temperatures of < 100°C used

Taste panel types - consumer preference groups

• Panels not specifically trained but constructed to provide insight as to what consumers prefer

Paper, paperboard & fiberboard

• Paper - thin, used for bags & wraps • Paperboard - thicker, more rigid, used to make single-layer cartons • Fiberboard - combined layers of paperboard used for secondary shipping cartons; also referred to as corrugated paperboard (i.e., cardboard)

Suspensions

• Particles too large to form colloidal dispersions • Unstable, suspensions settle-out due to gravity - Ex: uncooked starch grains

Bleaching

• Passing heated oil over charcoal or adsorbent clays and earths • To remove plant pigments such as chlorophyll and carotene

Time

• Peak time for quality is usually immediately or soon after harvest, slaughter or manufacture • Exceptions for foods aged or fermented (cheeses & wines)

External cues - Names & first impressions

• People drank wine from Cali and North Dakota and rated Cali wine better

External cues - Exercise

• People who viewed walk as "fitness" rather than "scenic" ate more dessert at dinner

Degumming

• Phospholipids and protein-fat complexes are gummy (undesirable) • When wetted with water, these compounds become oil-insoluble and settle out

With drying (in summation)

• Physical shrinkage • Distortion of cells and capillaries • Chemical and physical changes at the colloidal level • Loss of volatile flavor components

Fluidized bed freezing

• Placement of high-velocity nozzles underneath food on conveyor belt or tray whereby small food portions are subdivided and moved by cold air

Granulated sugars: The process

• Planet material is crushed and sugar is pressed out • Juice is filtered, clarified and evaporated • Raw sugar further refined by dissolving, purifying, and recrystallizing • Wet sucrose crystals pressed into a cube or table - lump sugar

Pectic substances

• Polymers of sugar acids • Water-insoluble, but mild hydrolysis produces water-soluble pectin that forms gels (e.g., jams & jellies, fruit preserves) • To firm F&V texture, add calcium salts

Tea components

• Polyphenolic substances (tannins) contribute of the flavor profile, especially astringency (the 'pucker' sensation) • Fermentation oxidizes the polyphenols to a more hearty aroma and flavor • Antioxidants are valued • Green and black tea have 10x amount of antioxidants found in F&V

Popular dishes

• Poultry (69%), followed by pizza (44%), soup, fish/seafood, sandwiches, burgers

High-power ultrasound (HPU)

• Power ultrasound is 20 - 100 kHz (high frequency ultrasound is 100 kHz - 1 MHz and diagnostic ultrasound is 1 - 10 MHz) • Will inactivate microorganisms, but the degree is modest; HPU generally enhances other methods of inactivation; best results in water

H2O functions

• Predominate ingredient in most foods • Contributes to food texture, but contributes no calories • Can contribute to food deterioration • Almost all food processing techniques involve water control

Munsell system - hue

• Predominate reflected wavelength (which determines the perceived color

Steps of ice cream manufacture

• Prepare ice cream mix • Mix is pasteurized • Pasteurized mix is homogenized • Aging the mix (increases viscosity) • Cold mix pumped to continuous freezers • Freezing quick

Presence of air in product

• Presence of air in food tissues leads to deformation from pressure treatment • Air in food can also enhance oxidative reactions

Reasons to use dehydration

• Preservation • Reduction of weight and bulk • Convenience • Maximum rate of drying is the focus

Additional fat processing methods

• Pressing or expelling - Squeeze oil from oilseeds - Usually cooked slightly to breakdown cell structure and enhance release of oil - For some seeds, only the germ is pressed - Crude oil usually clarified by filtering or centrifugation

Vapor pressure

• Pressure exerted as molecules of a liquid attempt to be in the gaseous rather than the liquid state

Agitating retort

• Pressure-cooking with movement

Pressure denaturation of proteins

• Pressures have little effect on covalent bonds, but do affect hydrophobic bonds and electrostatic interactions • At pressures >200 MPa denaturation usually is irreversible

Hazard Analysis and Critical Control Points (HACCP)

• Preventative food safety system in which a process for manufacturing, storing and distributing a food product is carefully analyzed step-by-step with a goal to eliminate a problem before it occurs • Focus is safety

Gluten

• Principal functional protein of wheat flour • Forms elastic dough due to linkages among protein molecules • Artifact of processing flour and does not exist in wheat kernel

Food concentration of fluid foods

• Principal reason to concentrate is to reduce weight and bulk • Types: Solar concentration for concentrating salt solutions, vacuum evaporators, freeze concentration

Radiation Indirect effects (vs. m/o)

• Probably more important than direct effects for inactivating m/o • Foods mostly water; water molecules altered to yield hydrogen and hydroxyl radicals and by-products such as hydrogen peroxide

Nonthermal facts

• Process optimization work needed for prototype methods • Delivery of more power for thoroughness and consistency of effectiveness • Application of hurdle concept • Identify niche applications/products • Anticipating/Predicting emerging pathogens and resistant mutants will stay a challenge

Advantages of a continuous system

• Produce less heat damage (i.e., very fast heating) • A more efficient operation (i.e., higher through-put) • Can be coupled with an aseptic packaging system

Dried corn syrups

• Produced by spray or vacuum drying for use in dry beverage mixes

Guarana

• Produces berries with twice the caffeine as coffee beans (up to 4.5%) - energy booster • Has GARS status

Changes during concentration

• Production of cooked flavors and darkening of color • Caramelization of sugar • Sandiness • Protein denaturation • Microbial inactivation although not sterile

Organic food sustainability

• Production of these foods is more environmentally friendly since the use of renewable resources and conservation of land and water are emphasized • Organic farming systems rely on ecologically based practices, such as cultural and biological pest management

Proteins

• Protein affects insulin activity and contributes to thermogenesis • Both type and amount of protein influence satiety • High-protein meals delay stomach emptying

Heating (thermal processing)

• Reasons to heat: Cook, pasteurize, blanch, evaporate, develop flavors, inactivate natural toxic substances (as with soybean meal) • Heat control is critical • Rapidly heat & cool • Retort versus heat exchanger

Betalains

• Red water-soluble pigments, but less frequently found in plants • Ex: Red beets • Heat-sensitive

Getting the trans out

• Reduced by reformulation methods • Interesterification of different oils to generate processed fats with different properties • Fractionation separates different components of an oil

Hydrogenation - health implications

• Reduced levels of PUFAs • Converts some cis double bonds of PUFAs to trans • Trans fatty acids elevates serum cholesterol

Vacuum evaporation

• Reduced pressure for lower temps

Innate™ potato

• Reduces postharvest waste and produces less acrylamide during frying • Reduces nonenzymatic browning (i.e., Maillard browning) due to slow degradation of starch to reducing sugars, such as glucose

High-intensity pulsed polychromatic light

• Reduction of 2 to 6 log10 CFU/mL bacterial pathogens with 200 pulses. • Lethal mechanism involves energy absorption by conjugated C=C bonds in proteins and nucleic acids leading to molecular disruption. • Pulses induce photochemical and photothermal reactions in foods, possible effects to sensory quality; shadowing concerns

Leavening process

• Refers to source of leavening gases • Gases must be trapped and held to expand dough or batter

Hypobaric storage

• Refrigerated storage under reduced pressure and high RH • Reduced pressure lowers oxygen levels and high RH prevents product dehydration; fruits & vegetables, meats & seafoods

Freezing vs. refrigeration

• Refrigeration = 4.5 to 7°C (40 to 45°F) • Most foods do not freeze until about -2°C (28.4°F) • Optimum frozen storage = -18°C (0°F) or lower

Controlling

• Regulation of all unit operations involved in manufacturing a food is a unit operation itself • Monitoring of automated equipment

Soft wheat

• Relatively low in protein, yields a weaker flour that forms doughs and batters better for cake-making

Buttermilk

• Remains after butter is churned from cream • Lactic acid bacteria may be added to pasteurized sweet cream for better flavor and keeping quality

Deodorization

• Removed by heat and vacuum, or adsorption onto activated charcoal

Lard

• Rendered hog fat; the oldest culinary fat • Rendering = fatty tissues heated and melted fat separates; lacks uniformity • Excellent shortening power (ability of fat to cover a large surface)

Evolutionary examples - sweet

• Represents a good nutrient source, carbohydrates; taste signals release of insulin

Heat preservation - canned foods

• Required heat treatment will be different depending on the retort, the size and shape of the containers, and the composition of the food

Air circulation & humidity control

• Required to move heat away from food surface • Air too moist = surface condensation and mold growth • Air too dry = foods will dry out • Each food has a characteristic optimal temperature and relative humidity (RH) for storage; usually best RH is equivalent to moisture content of the food itself

Molasses

• Residue remaining after sucrose removed from concentrated juices of sugar cane • Sugar content depends on what point of process derived from - After first = light color, high sugar - Final = dark and bitter

F&V Storage and ripening (S&R)

• Respiration after harvest can result in changes in carbs, pectin • Sweet ripe corn - sugars decrease/starches increase • Unripe fruit - is low in sugars, high in starches • Potatoes kept >10°C to keep reducing sugars low and reduce Maillard browning

Big three - Feeding the world

• Rice - directly to humans (>90% grown in Asia) • Wheat - directly to humans (>66MM metric tons/yr produced) • Corn - most to animals (globally >470MM)

Turgor

• Rigidity of plants from being filled with water • Most important factor affecting the texture of F&V • State depends on osmotic pressure

Rodents

• Rodents both consume and contaminate food • Control is critical since mice and rats can reproduce very quickly • Can spread disease

Vegetables

• Roots, leaves, stems, buds • Culturally, eaten with the main course of the meal

Sulfur dioxide dip (processing example)

• SO2 stabilizes the color of fresh & processed F&V • Is an antioxidant (inhibits activity of common oxidizing enzymes → reduces enzymatic browning) • Reduces Maillard browning • Interferes with microbial growth

Benefits of fermentation

• Safety & preservation • More nutritious • Variety added to our diet

Peanut Butter

• Salt added to peanut butter - Halite is salt rock (only natural rock consumed by humans)

Measuring flavors

• Salt, sugar and acid can be measured using instrumentation (e.g., use a pH meter to measure acidity) • To the complex: Eight-hundred to 1,500 flavor compounds identified in coffee • Analytical instruments can be used, but the human "test animal" is still best

Overeating

• Satiety inhibits ghrelin (increases hunger) and stimulates leptin (decreases appetite)

What is food science?

• Scientific study of food from "farm to fork"

Problems with ohmic heating

• Scorching/fouling of electrodes • Particulates/solid pieces pose a problem depending on size and conductivity • Issues of cost • Safety concerns with low-acid, particulate foods (e.g., spores)

Immersion refrigerants

• Solutions of sugars, NaCl, and glycerol • Immersion freezing usually limited to packaged foods because of problems of undesirable flavor transfer or other sensory issues

H2O uses

• Solvent • Ionizing medium for acids and bases • Environment for cellular metabolism • Heating and cooling medium • Cleansing agent

Fungal foodborne illnesses

• Some molds produce mycotoxins • Some mycotoxins are mutagenic and carcinogenic

Appearance factors - shape

• Some of the most difficult food engineering problems are the designing of equipment to pack odd-shaped food pieces

Natamycin - a polyene antibiotic

• Sorbic acid is being replaced by natamycin, which Kraft says is a "natural mold inhibitor"

Evolutionary examples - sour

• Sour taste an indicator of food spoilage

Stevia or Reb-A (or Stevioside)

• South American herb used as a sweetener • From leaves of the small, green Stevia rebaudiana • "No calories, no tooth decay, and totally natural" (from plant extract); FDA-approved; heat-stable • 200-300X sweeter than sugar. • Currently most popular for use in teas and coffees • Disadvantages: Bitter licorice-like aftertaste, bloating, gas and allergic reactions

Tofu

• Soybean curd or precipitated protein of soy milk using calcium sulfate and calcium chloride • Adaptable for egg dishes, casseroles, breads, and vegetable and meat dishes

Different types of oils (facts)

• Soybean: >60% of vegetables oils, world's most popular edible oil • Palm: from fruit, currently 2nd to soybean • Cottonseed: America's first

Specific heat/"Energy sponge"

• Specific heat of water = 1 cal/g/1°C, or the energy necessary to raise temperature 1°C • Degree of hydrogen bonding may make specific heat of water higher than similarly sized compounds - Takes considerable energy to heat water - Water takes up considerable heat to evaporate - Water is a very good cooling agent

Pasteurization - Milk & Liquid Eggs

• Specifically designed to destroy pathogens associated with the food having public health significance

HPP and spores

• Spores germinate due to exposure to pressure or heat, lose their resistance, and are subsequently inactivated • HPP sterilization of low-acid foods is a fundamentally unreliable process • Hurdle approach: Add more heat and/or lower pH

C. bot Intoxication

• Spores widely distributed in nature and frequent in raw food, but occurrence of human botulism rare - Infant botulism - Wound botulism - Botox

Microencapsulation

• Spray-drying emulsified components with gelatin, gum arabic, etc. ,to form a thin protective coating around each food particle

How do we create a safe product? (MP)

• Start with good ingredients • No thermal kill step • High quality wash water & flume water • Ice and other packaging materials

Aseptic packaging/UHT

• Sterilization (temperature high enough to sterilize a food in 1 to 2 seconds) • Sterile food must be quickly cooled to room temperature using heat exchangers • Developed for volumes as large as silo tanks and railroad tank cars

Caffeine effects on human body

• Stimulates brain cortex, gastric secretions, action of the heart • Widens blood vessels • Increases water elimination, blood sugar, effectiveness on painkillers • Alters activity of calcium ions making muscles less susceptible to fatigue

Keeping quality

• Storage stability

Molecular gastronomy

• Style of cuisine in which chefs explore culinary possibilities by borrowing tools from the science lab and ingredients from the food industry

Freezer burn

• Sublimation or a form of freeze-drying (moisture loss) producing undesirable food surfaces, nutrient loss, and other defects

Cryogenic liquids

• Such as compressed liquid nitrogen (boiling point of -196°C) and carbon dioxide (-79°C) • Cheaper powdered dry ice (CO2) can be mixed with food to be frozen or liquid CO2 can be sprayed under pressure onto food

Constituents that protect microorganisms against heat

• Sugar, starch and proteins in high concentrations • Fats and oils interfere with wet heat penetration • Different compositions of container/packaging have different degrees of heat transfer • Use of salt

Types of oil

• Sunflower: Good stability • Peanut: Excellent oxidative stability • Olive: Most expensive edible oil; virgin refers to olive oil from the first pressing • Corn: Used principally in margarines • Canola: From rapeseed • Safflower: Highest content of PUFAs • Coconut: High in saturated fat

PA 3679

• Surrogate for C. botulinum type A (PA 3679 spores are used)

Functional properties of sugars

• Sweetness and other flavors • Color (from Malliard browning & degradation) • Texture • Mouthfeel

Starch

• Swell and gelatinize when exposed to moisture and heat • If granules stay, tissue becomes plump • If plant cells burst, lose firm texture

Carbonated Drinks Procedure

• Syrup contains flavorings, coloring, acid and preservative that are thoroughly mixed before-hand • Syrup is diluted with water and carbonated in a pressurized CO2 vessel (a carbo-cooler) • Liquid is packaged

HACCP - hazard analysis

• Systematic study of the ingredients, food product, conditions of processing, handling, storage, packaging, distribution, and consumer use

Fat replacements

• Taking proteins and carbs and processing them to produce ingredient that has some of the properties of fat without calories or artery-clogging properties • Polydextrose and Maltodextrin (starch-based)

Butter

• The fat of cream that is separated from other milk constituents by agitation (churning) • "Water-in-oil" emulsion (18% water & 80% fat); a small amount of protein acts as the emulsifer

Amylose (1/2 starch fractions)

• The linear fraction; slightly soluble

Magnetron

• The microwave generator; it's an electron tube within a magnetic field which propagates high-frequency radiant energy

High fructose corn syrup (HFCS)

• The most heavily used ingredient sweetener • Development of HFCS manufacture a direct result of Castro's revolution in Cuba due to embargo of Cuban cane sugar in U.S.

Food irradiation (Nutrient content and absorption)

• The nutrient content of some foods is altered because some of the B-group vitamins are reduced; this loss is similar to other food-processing techniques, such as canning or blanching • The dose of radiation that a substrate receives is important; different materials absorb radiation energy to different degrees

Essential oils as preservatives

• The oils of bay, cinnamon, clove and thyme are the most inhibitory to bacteria, each having a bacteriostatic concentration of 0.075%

Aeroponics

• The process of growing plants in air or a mist environment without soil or medium

Shelf-life is dependent on...

• The processing method(s) • Packaging • Storage conditions • The food

Factors affecting HMT - Surface Area

• The smaller the volume the larger the relative surface area • A larger surface area (or a smaller food portion) provides more surface in contact with heating medium and more surface to allow escape of water

Cocoa and chocolate

• Theobroma cacao is cultivated only within 20 degrees of the equator • West Africa is largest producer • Originated from Central America

Government standards

• There are many types, some voluntary, some mandatory

Bacillus and Clostridium

• These bacteria are the most important sporeforming organisms in foods • Most species of these genera of bacteria are spoilage agents

GM crops

• Those varieties produced through the introduction of pieces of DNA to give them traits otherwise not possible

Shelf-life

• Time it takes for a product to deteriorate to an unacceptable level (it is a matter of opinion what unacceptable is)

Processor Optimal Heat Treatment

• Time-temperature combination = inactivate heat resistant pathogens and spoilage organisms • Do not want to excessively heat-treat food • Heat-penetration characteristics in a particular food & container

Why do we taste?

• To help us detect and respond to needed nutrients • That people and animals with dietary deficiencies will eat foods high in certain vitamins and minerals All animals and humans generally reject acids and bitter-tasting substances; responses are present at birth and located in lower brain stem

Refining

• To settle additional minor impurities from oil missed by degumming • Free fatty acids combine with alkali to form soaps

Drying

• To take foods to near total dryness (2 to 3% water) • Spray drying, drum drying, freeze-drying, long tunnel ovens

Decaffeination

• Too much caffeine leads to irritability and irregularities • Achieved by solvent extraction with methylene chloride (carcinogenic)

Ice cream defects

• Too much lactose • Shrinkage • Dipper loss = mechanical compaction when ice cream dipped from tubs to make cones • Poor mix formultations

Trend - ethnic everything

• Top 3 = Italian, Mexican, Chinese

Xanthohumol

• Toxic to several kinds of human cancer, including prostate, ovarian, breast, and colon • Inhibits enzymes that activate cancer development • Slows tumor growth in early stages

Food safety: Traditional foods

• Traditional foods can contain naturally occurring toxins present in concentrations that are not hazardous to consumers ingesting typical quantities of the food • About 10% of world's crops now GMO; 70% processed food contain GMO ingredients

Pasteurization

• Treatment below the boiling point of water and dependent upon type of product • Normally requires additional means of preservation (e.g., the refrigeration of milk)

Aromatization (for instant coffee)

• Treatment to improve flavor and aroma • Usually involves adding back flavors and aroma constituents trapped and recovered during processing • Constituents are usually oils

Hydrolytic fat rancidity

• Triglycerides breakdown and fatty acids are released • Caused by lipases and heat • May destroy nutrients in food • Short-chain fatty acids produce very disagreeable odors and flavors

Oxidative fat rancidity

• Triglycerides breakdown when unsaturated fatty acids exposed to oxygen, resulting in highly reactive derivatives that produce unpleasant rancid odors and flavors • Most responsible for spoilage of fats and fatty foods • Vitamins A & E lost

Cocoa fermentation

• True fermentation by natural microbial populations of plant • Desirable because gelatinous pulp digested away, plant embryo killed by heat generated, desirable flavors produced

Unsaturated solution

• True solution capable of dissolving additional solute at temperature of solution

Saturated solution

• True solution containing as much solute in solution as possible at temperature of solution

Supersaturated solution

• True solution containing more solute than can be dissolved at that temperature (created by cooling a saturated solution)

Triglycerides - melting point

• Types of fatty acids largely determines properties of triglyceride • Fats high in saturated fatty acids solid at room temp. (unsaturated = liquid) • Long fatty acids increase melting point • All food fats are mixtures (fats do not have sharp melting pt)

High-fructose corn syrup (HFCS) (% fructose)

• Typically 55% fructose, 45% glucose or 58% glucose, 42% fructose

Ultrafiltration & reverse osmosis

• Ultrafiltration uses synthetic membranes made of cellulose acetate or polyamide • Type of membrane used is specific for each food and use • Pores of membranes for reverse osmosis smaller than those used for ultrafiltration

HPU Mechanism

• Ultrasound generates bubbles within a liquid/slurry called cavitation; as bubbles collapse, energy is released which is detrimental to the cell

Shrinkage

• Uniform shrinkage seldom seen in foods; water is not removed evenly • Rate of drying will affect shape and density of food particles

Evolution of organic foods

• Up until the late 1980s any merchant could label their food "organic" without it necessarily being a true claim. • USDA standards passed in 2001

Fiber to modulate satiety

• Use as food additive or as a dietary supplement • Ex: Guar gum and alginates in beverages; oligofructose as supplement

Use of microwaves by the industry

• Use complex microwave tunnel ovens with a moving belt of low-loss material; food is conveyed past the magnetron continuously. • To heat fluid foods continuously, the liquid is pumped through a low-loss glass tube and the magnetrons are positioned around the tube • Cost a big factor in their industrial use

Taste panels

• Use of groups of people preferred over an individual opinion as differences of opinion tend to average-out; statistical analysis of data • No more than 5 samples tested at one sitting, sense of taste becomes dulled • Also judge texture, color, packaging, sample arrangement, etc., i.e., sensory panels

Hurdle concept

• Use of multiple food preservation factors to eliminate or prevent growth of pathogens and spoilage microorganisms while maintaining the desirable sensory quality of the food • This concept stresses the improved antimicrobial efficiency of incorporating as many "hurdles" to microbial growth as possible and using these hurdles synergistically in an overall strategy to eliminate that growth

Crystalline fructose

• Used mainly by food processors • It thickens more rapidly and has greater gel strength than sucrose

Basics of refrigeration

• Uses evaporation of a liquid to absorb heat (e.g., as sweat evaporates, it absorbs heat; rubbing alcohol feels even cooler because it evaporates at a lower temperature) • Refrigerant used in refrigerators evaporates at extremely low temperatures (e.g., pure ammonia evaporates at -27°F)

Hydroponics

• Uses water as a growing medium and essential minerals to sustain plant growth without soil

Measuring human preference - preference test

• Usual approach • Choosing one sample over another (samples are coded so food sample identity is unknown)

The Dutch Press

• Van Houten (1828) invented the cocoa press - Enabled the removal of cocoa butter • Milk chocolate was invented in 1876 by Daniel Peter in Switzerland

Fruits (in general)

• Varietal differences • Maturity is when the fruit is ready-to-eat or be harvested • Ripeness is the optimum condition when color, flavor and texture have developed to peak

Vegies (in general)

• Varietal differences • Peak quality lasts only briefly • Different responses to cold storage

Laminates packaging

• Various flexible materials • Multilayers or laminates of these materials combining the best features of each are used as packaging materials • May contain as many as eight different layers

Mixing

• Very common (solid-solid, solid-liquid, etc.) • Kitchen style, just bigger • Common ex: propeller-type agitator within stainless steel vat • Hobart™ - a leading name

Light

• Visible light is a source of energy • Inactivates some vitamins and causes deterioration • Opaque packaging will protect light-sensitive foods

Coca-Cola

• Was originally green • 1906 Pure Food and Drug Act forced removal of cocaine • National advertising emphasized

True solutions

• Water dissolves small polar molecules such as salts and sugars - For example: add NaCl to water → Na+ Cl- • Solutions are generally stable • Solubility increases with increasing temperature

How light beers are made

• Water it down • Add α-amylase (converts dextrins to alcohol) • Add glucose (in place of some barley malt) • Use amyloglucosidase (breaksdown all dextrins to fermentable glucose)

Mechanism of heating

• Water molecules are polar • When microwaves pass into a food, water molecules orient in the direction of the electric field. • When the electric field reverses 2,450 or 915 million times/second, inter-molecular friction generates heat. • Generated heat is also conducted among food components

Freeze drying

• Water will sublime if the temperature is ≤ 0°C and pressure is ≤ 4.7 mm; structure of food is usually quite porous

Margarine: FDA standard of identity

• Water-in-fat emulsion containing at least 80% fat, emulsifiers, salt, butter flavor, color, preservatives as well as vitamin A & D

Principles of baking

• Wheat flours primarily used in baking Most products leavened (raised)

Gluten & starch

• Wheat starch does not form elastic films • Gluten + starch form a batter or dough depending on amount of water used • Stronger flours contain more gluten (vice versa)

Wheat flour

• Wheat usually first converted to flour

Shortenings & emulsifiers

• When used in baking, contain monoglycerides and diglycerides to allow higher proportions of sugar and liquid to be added • Addition of emulsifiers lowers the smoke point of fat → not desirable for frying

Domestication

• Whereby a population of living organisms is changed at the genetic level through generations of selective breeding • Ex: plants retain seeds, stand upright and ripen simultaneously

What provides extra protein & fiber to food (such as quaker weight control)?

• Whey protein isolate provides the extra protein • Oat flour and guar gum contribute soluble fiber

High-temperature/short-time pasteurization

• Widely used in the food industry. • Continuous process; raw milk held in a cool storage tank and pumped through a heat exchanger and cooled again. • Milk held at least 71.7 °C for 15 seconds

External cues - Mimicry effect

• With a fast eater, people consumed more calories than eating alone; vice versa when paired with a slow eater

Taste panel types - highly trained people

• With heightened taste sensitivity and knowledge of product

Aflatoxins

• Worst thing that fungi can deliver to foods • Aflatoxins can be found in cereals, grains and nuts • Common contaminants

Beer fermentation

• Wort pitched with yeast Proceeds at controlled temperature "Green beer" filtered and lagered Filtered/clarified to remove last remnants Pasteurized, charged with CO2 & packaged

Taste panel type - random volunteers

• Yea

Four categories of bakery products

• Yeast-raised goods (breads) • Chemically leavened goods (donuts) • Air-leavened goods (angel cakes) • Partially leavened goods (pie-crusts)

Water & air assist in leavening

• Yeasts and baking powders (produce CO2) • Water turns to expanding steam in oven & leavens • Air in dough expands and contributes to leavening

Glucoamylase

• Yields more glucose (high-glucose syrups have lower viscosity and higher sweetening power)

β-amylase

• Yields more maltose

Foods labeled organic...

• must be certified by an agency that has been accredited by the USDA and can use the USDA organic seal

GMO - closing facts

• rDNA techniques represent an important advance in food technology • rDNA technology will not solve all the world's problems concerning hunger and disease, but it will help

Safety of introduced genetic material

• source of genetic materials • size of genetic construct • number of copies inserted • location of insertion • base sequence

White crystalline glucose

• ~75 to 80% as sweet as sucrose • Made from the complete hydrolysis of corn starch