DSCI 231 Final

bone and teeth

-99% of calcium in body -skeleton contains 2-4 lb Ca; serves as Ca reserve; used for other functions at the expense of bone; blood levels are tightly controlled -slightly flexible living tissues- continually undergoing remodeling; constant turnover

osteoporosis risk factors

-Caucasians or Asians (uncontrollable) -age (uncontrollable) -female (uncontrollable)- males have higher peak bone mass, which means denser bone, and more reserves upon which to draw; menopause leads to low estrogen, leading to bone loss; women live longer -low Ca intake (controllable) -inactivity (controllable)- weight bearing exercise stimulates bone formation; run/walk/sporting activity

synergism between yogurt starter cultures (draw diagram from slides)

-L. delbrueckii ssp bulgaricus (produces formic acid and carbon dioxide) and S. thermophilus (produces small peptide and amino acids) grow together in yogurt -each produce certain metabolites or breakdown products that are released into the medium and stimulate the growth of the other organism -these are synergistic since each produces certain metabolites that stimulate the other growth

step 3: inoculation of yogurt mix (yogurt making)

-Lactobacillus delbrueckii ssp bulgaricus and Streptococcus thermophilus in a 1:1 ratio -rod to coccus ratio= 1:1

buttermilk cultures

-Mesophilic lactic acid cultures, containing: Lactococcus lactis (Lc l), Lactococcus cremoris (Lc c), Lactococcus diacetylactis (Lc d), Leuconostoc mesenteroides subsp. cremoris (Leu c) -CO2 is also produced

glycosidic linkage

-a chemical bond that joins two simple sugars via an oxygen atom

yogurt

-a fermented dairy product, resulting from the growth of Lactobacillus delbrueckii ssp bulgaricus and Streptoccus thermophilus -other LAB may be included -sugar, colorant (dye), fruit, and stabilizer may be added -smooth, viscous gel with delicate flavor -preferably contain live bacteria -contains not less than 3.25% milkfat and not less than 8.25% milk solids not fat and has a titratable acidity of not less than 0.9% expressed as lactic acid -low fat yogurt- >0.5% and <2.0% fat -nonfat yogurt- <0.5% fat

food allergy

-an adverse reaction to a normally harmless substance in food (almost always a protein) that involves the body's immune system -an abnormal immune response to a food -US- between 3.5-4% of the population (about 10-12 million Americans) have food allergy -estimated that about 29,000 emergency room visits and 150-200 deaths occur from food allergic reactions each year -90% of allergies: peanut, tree nuts, milk, egg, soy, fish, shellfish, wheat

food intolerance

-an adverse reaction to a normally harmless substance in food that does NOT involve the body's immune system -metabolic food disorders: lactose intolerance -idiosyncratic (sensitive) reactions: sulfites, monosodium glutamate (MSG)

calcium

-an essential macromineral -most abundant mineral in our body; mostly in bones and teeth -functions: bone matrix, nerve function, cellular metabolism, blood clotting, muscular contractions, enzyme activation -milk and dairy are good sources -dietary guidelines: 3 servings per day -AI's (not RDA's) and UL's have been established -low intake is one of the risk factors for osteoporosis -highest amount in low fat yogurt; more in skim than whole milk -people typically do not meet daily requirement

yogurt cultures

-basic cultures are all to contain L. bulgaricus and S. thermophilus -other strains: Lactobacillus helveticus, Lactobacillus jugurti, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophilus, Bifidobacterium -cultures are thermophilic: optimum growth temperature= 108F (42C) sometimes called the "Rod and Coccus" cultures: Streptococcus thermophilus (coccus), Lactobacillus delbrueckii ssp bulgaricus (rod) -provide classic example of symbiosis- both cultures can achieve a much higher final number in the presence of the other than it can alone

structure of bone

-dynamic material constantly undergoing turnover (growth, resorption/breakdown, re-growth) -two main types: cortical (dense outer shell), trabecular (spongy inner network)

kefir production

-fat standardization -homogenization -pasteurization and cooling to inoculation temp (similar to cultured buttermilk) -inoculation with kefir cultures -two-stage incubation: acidification stage (LAB produce lactic acid for 12 hours at 72F); ripening stage (yeast produce alcohol for 12 hours at 57-60F) -cooling and packing

kefir

-fermented milk (from goats, sheep, or cows) -drinks popular in Russia -viscous homogenous like cultured buttermilk, pH 4.4-4.5 -unique yeast aroma; yeast is part of the starter culture -usually contains no alcohol -culture ("kefir grain"): proteins, polysaccharides, LAB, yeast; LAB- lactic acid; yeast- alcohol -culture is produced from kefir the day before; may vary batch to batch

tolerable upper intake level (UL)

-highest level of nutrient intake daily that will not pose a risk of adverse effects for most people in the population -as you increase intake above, your risk for adverse reactions increase -major difference between the DRI's and the old RDA's as they never offered the highest level that could be consumed

step 4: incubation (yogurt making)

-in cups (set type)- filled containers put on trays or shelves on movable racks and placed in the incubation room; constant temperature room (108-110F); on a conveyer belt through a tunnel at incubation temperature -in vats or fermentation tanks (stirred type)- yogurt is cooled rapidly at the end of the incubation period -108F (thermophilic starters) for 4 hours -mix should not be inoculated until it is known that downstream processing/packaging equipment will be available at the needed times

fermented milks

-inoculated with a careful selection of culture of LAB or yeast -yogurt, cultured buttermilk, kefir

end products in yogurt

-lactic acid (flavor, texture, preservation) -diacetyl, acetaldehyde (flavor) -exopolysaccharides (texture)- "ropy/slimy" cultures produce a polysaccharide that had a molar ratio of 1 part glucose and 2 galactose; electron photomicrographs show that the slime connects the bacterial cells to the protein constituents of yogurt

adverse dairy food reactions

-lactose intolerance -milk allergy -dairy products containing or contaminated with other food allergens -imitation products originated from allergic food materials -soy cheese, almond milk, etc.

lactose intolerance

-lactose maldigestion -persons unable to metabolize lactose in dairy products -associated with a deficiency of the intestinal enzyme, lactase -decline with age -lactose fermented by bacteria in colon: gas production, increase osmotic pressure in colon (water not absorbed) -symptoms: abdominal pain, "rumbling in the bowel," flatulence, bloating, diarrhea -occurs in about 25% of US adults -affects 60-90% in some ethnic groups -"treated" by avoiding dairy; drawback- low Ca intake (need 3 servings of milk products to get enough Ca; 75% of dietary Ca comes from dairy) -should be able to have 1-2 servings of milk daily with meals without experiencing discomfort

osteoporosis

-loss of bone tissue to extent that skeletal site is unable to withstand ordinary strains -porous bones characterized by: low bone mass, structural deterioration of bone tissue, bone fragility, increased susceptibility to fracture -mature adults contain about 1200g of calcium in their skeleton; peak bone mass is the maximum bone mass achieved by 30 -life expectancy (at birth in 2001)- 79.8 years for women and 74.4 years for men -women live longer and have more time to lose bone calcium -more than 40 million Americans are at increased risk of bone fracture due to it; associated medical cost is estimated to be 18 billion dollars

yogurt manufacture

-milk and milk solids are used as substrate -heat at 175-185F for 30-60 minutes -Lactobacillus delbrueckii ssp bulgaricus and Streptococcus thermophilus in a 1:1 ratio; rod to coccus ratio= 1:1 -incubate at 108F for 3-5 hours -at the end of incubation, titratable acidity is 0.85-0.9% lactic acid -fresh yogurt contains 10^9 organisms per gram, but this number declines upon storage 1. preliminary treatment of milk (yogurt mix) 2. addition of other ingredients 3. homogenization of yogurt mix (optional) 4. inoculation with cultures 5. incubation 6. cooling and storage

food allergies

-more likely to develop if the individual comes from a family where allergies like hay fever, eczema, or asthma are common -can take on many forms -symptoms: milk to severe and even life threatening; reactions of the skin, GI tract, and respiratory system -skin symptoms: hives, rashes, swelling of the face and lips; itchy, painful, long-lasting eczema-type reaction; mild to severe; occurs minutes to hours after exposure -GI symptoms: nausea, vomiting, abdominal pain, diarrhea (mild to severe; can occur from minutes to hours after exposure; can mimic symptoms of foodborne illnesses) -respiratory issues: airways are affected; nose is runny; breathing problems or wheezing; tightening and closing of throat (can range from milk to severe and life-threatening)

trace minerals

-more than a dozen -iron, zinc, copper, manganese, iodine, selenium

anaphylactic shock

-most severe form of allergic reaction -several parts of the body simultaneously experience allergic reactions; a generalized shock reaction -symptoms include itching, hives, swelling of the throat, difficulty breathing, cardiac arrhythmia, low blood pressure, and unconsciousness -symptoms usually appear rapidly (often within minutes of exposure to the allergen)

public perception

-people use the term "food allergy" to describe problems they have with food -many people claim that they are "allergic" to dairy products, but they confuse with the true food allergy: metabolic food disorders and other non-immunological reactions to food

major minerals

-present in amounts larger than 5 g (a teaspoon) -1 pound is about 454 g; only calcium and phosphorus appear in amounts larger than a pound -calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium

excretion of Ca

-routes of excretion: urinary losses (100-240mg daily), fecal losses (45-100mg daily), sweat losses (60mg daily)

cultured buttermilk

-same as cultured milk -"fluid product resulting from the souring, by lactic acid producing bacteria or a similar culture, of pasteurized milk (cream, milk, partially skimmed milk, or skim milk, used alone or in combination); contains less than 3.25 percent milkfat and not less than 8.25 percent milk solids-not-fat" -not made from traditional buttermilk

prick skin test

-small amount of allergen tested on the patients by "pricking" the skin with a needle -response in about 15 minutes

frozen yogurt

-soft-serve or hard-frozen -two ways: yogurt mixed with an ice-cream mix; ferment the ice-cream mix

step 1: yogurt mix

-standardized or fortified to a high level of solids (around 15%) in order to achieve the desired body characteristics of the finished product -NFDM, WPC -sugar (or other sweeteners)- about 2-3% -colorants -stabilizers- up to 1%: pre-gelatinized starch or pectin

common yogurt styles in US

-sundae style (set type)- incubation in the cup; fruit can be placed on the bottom of the cup; flavorings such as vanilla can be added to the mix so that it can be in the yogurt portion of the cup -Swiss style (stirred type)- incubation in bulk tank, cooled and filled into cups; fruit and flavorings can be blended with the yogurt

step 2: heat treatment (yogurt making)

-temperature in range of 175 to 185F for 30 min -effects of the heat treatment: 1. bacterial load of the milk is reduced- less competition for starter cultures 2. denaturation of the whey proteins and an aggregation of the casein molecules into a three dimensional network- increase viscosity

food allergen labeling

-the Food Allergen Labeling and Consumer Protection Act -mandates plain English, allergen labeling for all foods containing major ("big eight") food allergens -signed into law of August 2, 2004 -effective January 1, 2006

adequate intake (AI)

-the recommended intake based on experimentally or observed approximations of nutrient intake by groups of healthy individuals, which are assumed adequate -used when RDA's can't be determined -for Ca: 1000mg/day for men and women (19-50), 1000mg/day during pregnancy and lactation (19-50), 1300mg/day for adolescents aged 9-18

disaccharides

-two sugar molecules linked together by glycosidic linkage -maltose: gluclose+glucose -lactose: galactose+glucose

allergens in food processing

-undisclosed allergens in raw materials -inadequate cleaning between formulations -formula/label mismatches -formulation errors -incorrect packaging -cross-contact from other processing lines or shared equipment

make buttermilk at home

-use active buttermilk as starter -add fresh milk to the starter -place in a warm part of the room

Does milk intake during childhood and adolescence decrease risk of osteoporosis?

-women aged 20-49: bone mineral content was 5.6% lower in women consuming less than 1 serving of milk per week compared to women consuming more than 1 serving of milk per day -women 50 and up: low milk intake as children was associated with a 2-fold greater risk of fracture -recommendations: 3 or more Ca rich foods daily; sun exposure and/or vit D fortified foods; regular exercise; avoid smoking and excessive alcohol intake; estrogen replacement therapy for post-menopausal women

low-lactose/lactose-free dairy products

-yogurt and fermented milk -cheeses such as cheddar -lactaid milk -lactase pills

milk allergy

-your immune system identifies certain milk proteins as harmful, triggering the production of antibodies to neutralize the protein (allergen) -two main protein groups in cow's milk that can cause an allergic reaction: caseins and whey proteins

harmless

Adverse Reactions to Food: 1. foodborne illness (food poisoning) 2. food intolerance 3. food allergy The last two involve the body's reaction to substances in food that are normally ________.

1-3 mg

Food Allergens: -current evidence indicates that amounts as low as ________ of food allergens can elicit milk allergic reactions in the most sensitive individuals

immunoglobulin E (imE), mast cells

Mechanism of Allergic Reaction 1. as food is digested for the first time, tiny protein fragments promote certain cells to produce ___________ against food 2. the IgE attaches to the surface of the ________ 3. the next time that food is eaten, the protein interacts with the specific IgE on the mast cells and triggers the release of histamines and other cellular chemicals 4. histamines and other chemicals produce the symptoms of an allergic reaction -sensitization and reaction

C

Starter culture used in sour cream manufacture is ___________. A. thermoduric B. thermophilic C. mesophilic D. psychrotrophic E. psychrophilic

epinephrine

Treatment of Food Allergies: -no curative treatments -susceptible people must avoid exposure to offending foods -an emergency plan must be in place to treat severe reactions caused by accidental ingestion -can result in multiple organ failure -emergency treatment is to administer an injection of ___________ -EpiPen available to allergic individuals -if not treated immediately, it can be fatal

false

True or False: Lactose intolerance involves our body immune systems.

true

True or False: Milk is one of the "big eight" food allergens.

false

True or False: The minimum titratable acidity for sour cream is 0.9%.

top 8 food allergies

peanut, tree nuts, milk, egg, soy, fish, shellfish, wheat

recommended dietary allowance (RDA)

the average level of daily dietary intake which is sufficient enough to meet nutrient requirements of 97- 98 percent of healthy persons in particular life stages and gender groups

yogurt definition

"the food produced by culturing one or more of the optional ingredients specified in paragraph (c) of this section with a characterizing bacterial culture that contains the lactic acid-producing bacteria, Lactobacillus bulgaricus and Streptococcus thermophilus. . . . Yogurt, before additional of bulky flavors, contains not less than 3.25 percent milkfat and not less than 8.25 percent milk solids not fat, and has a titratable acidity of not less than 0.9 percent, expressed as lactic acid"

acidified milk

"the food produced by souring pasteurized milk with one or more food grade acids, with or without the addition of lactic acid producing bacteria. Acidified buttermilk contains less than 3.25 percent milkfat and not less than 8.25 percent solids-not-fat and has a titratable acidity of not less than 0.5 percent expressed as lactic acid"

overview of manufacture of buttermilk

1. cream, milk, partially skimmed milk, or skim 2. pasteurization and homogenization 3. inoculation with cultures 4. incubation 5. agitation 6. cooling and package

epinephrine shot

What can be used as an emergency treatment for severe food allergic reactions?

decanter centrifuge

What type of equipment can you use to separate lactose crystals from a slurry?

D

Which method is used to reduce the lactose content in the retentate for the production of WPC 80? A. reverse osmosis B. spray-drying C. microfiltration D. diafiltration E. evaporation

E

Which of the following is not one of the big eight food allergens? A. peanut butter B. pasteurized reduced-fat milk C. black coffee with hazelnut flavors D. tofu E. cocoa butter