Packaging 201 - Final

How many kilograys are required for radurization?

0.75-2.5 kilograys

How many orders of magnitude (logs) equal an F value?

12 logs

How many kilograys are required for radicidation?

2.5-10 kilograys

MAP modifies the atmosphere in a package, such that it is no longer __________

21% O2, 78% N2, and 1% CO2 and other gases

How many kilograys are required for radapperatization?

30-40 kilograys

What is the pH cutoff between "high acid" and "low acid" foods?

4.6

Maillard Browning is:

A browning reaction initiated in the presence of amino acids and heat.

What is meant by the term "warmed over flavor?"

A different taste to the food following the initial time cooking it.

An element with an unpaired electron is called:

A free radical

What is a kilogray?

A measurement that measures the time and intensity of radiation.

Below what (Aw) level does bacteria usually stop growing?

About 0.8 (some may argue 0.7 up to 0.85, but 0.8 was mentioned in class.)

What effect does adding bacteria have on a product? Provide an example.

Adding bacteria lowers the pH, creating a more acidic product (usually a sour taste.) Ex/ beer, wine, cheese, yogurt, etc. Cottage cheese vs. blue cheese have different bacteria levels, with cottage cheese being less acidic. Lower pH cheeses have a longer shelf life.

What are the monomer units comprising proteins, carbohydrates, and lipids?

Amino Acids - Proteins Monosacchrides - Carbs Fatty Acids and Glycernol - Lipids

The two main constituents needed for maillard browning to occur are an _______ and a ______, in the presence of heat.

Amino Acids and sugar

What is irradiation?

An additional way to sterilize foods. Uses Colbalt 60 (gamma) or Electron beam (e-beam) irradiation. Can calculate doses for irradiation based on food product and size of package

In what stage does ripening take place?

At the end of maturation and the beginning of senescence.

A type of sterilization that uses pressurized water at high temperatures is called ______.

Autoclaving

Define Aw through ERH.

Aw = ERH/100

Is bacteria aerobic or anaerobic?

Bacteria can be found in both categories

Anthocyanins give off the color ______.

Blue, like the color found in blueberries.

The ______ the number of double bonds present, the ______ the absorption will be in longer wavelength regions. (Appears red)

Greater, greater

What are the three phases that fruits and vegetables pass through?

Growth, maturation, and senescence.

What is the HACCP's job?

HACCP helps identify points in processing where food safety issues might arise, thereby highlighting critical points to control in the line. Example in class was deli meat.

The compound responsible for the burnt taste in Maillard Browning is _______.

HMF

What does HACCP stand for?

Hazard Analysis and Critical Control Points

What is pasteurization defined as?

Heat treatment to the point that you kill pathogenic microorganisms but not all of the microorganisms. Uses lower temperature.

What is convection heating?

Heating by transferring fluids from one place to another. Much faster process than conduction heating.

__________ are a large contributor to post harvest decay.

High temperatures and high humidity.

_______ bonds are relatively easily broken with the application of heat.

Hydrogen

Surface tension in water is a result of ________.

Hydrogen (dipole) bonding

What is the definition of cooperative hydrogen bonding?

Hydrogen bonding occurs when an atom of hydrogen is attracted by rather strong forces to two atoms instead of only one, so that it may be considered to be acting as a bond between them.

______ is the insertion of water into separate components, results in individual amino acids, requires water, and severs with water.

Hydrolysis

How can you prevent chemical reactions of pathogens in food?

Remove moisture or bind it with sugar or salt. Control moisture --> control bacteria levels. Ex/ Beef jerky is dehydrated meat, won't allow pathogens to grow.

What is an aerobic microorganism? Provide an example.

Requires oxygen for growth and can die without it. Example: Mold.

Define viscosity.

Resistance to flow.

What are the two moisture sorption isotherms?

Resorption isotherms and desorption isotherms

What are the characteristics of climacteric fruits?

Ripening is associated with distinct increase in respiration and ethylene production. Treating the fruit with ethylene stimulates respiration. (Ex/ bananas)

What are the characteristics of nonclimacteric fruits?

Ripening is protracted and the ripe state is not associated with a marked increase in respiration or ethylene production. (Ex/ strawberries)

What isotherm shape is characteristic of most food?

Sigmoidal

What is the importance of water in foods?

Stabilizes the food, inhibits spoilage, inhibits microbial growth, increases shelf life of the food.

Define autoclaving:

Sterilization under a hot pressure stream

Respiration is a good indicator of the:

Storage Life

A Z value is defined as:

Temperature increments (∆T) which speeds up the destruction of microorganisms by a factor of 10 (1 log) or lowers the rate by a factor of 10 (1 log.)

The level of protein organization that determines how a protein functions is _______.

Tertiary

What four groups are pigments broken into?

Tetrapyrole compounds, isoprenoid derivatives, benzapyran derivatives, and artefacts.

What is water activity and what is the abbreviation used?

The amount of water available for chemical reactions to occur (Aw)

What are thermal Death Curves used for?

To determine the time it takes to reach commercial sterility in foods.

What is the total moisture content?

Total mass of water in a system per total mass of food (g wt. H2O/g wt. dry food)

What is the difference between total moisture content and water activity? How do they affect packaging and storage?

Total moisture content is all the water available. Water activity is only water free for chemical reactions. Aw can make it easy for bacteria to grow. Dividing line is 0.8 Aw. Stronger packaging methods may be needed to keep microbials at bay or product could require refrigeration (added cost.)

The y-axis of the above graph indicates ______, while the x-axis indicates _______.

Total moisture content, water activity

Water can be categorized as three types: ____, _____, and _____. What is meant by these types?

Type I, Type II, and Type III. I is bound and impossible to remove. II is bound but can be removed by actions like heat. III free water ready for chemical reaction.

What is the USCDC?

United States Center for Disease Control

What does USDA stand for?

United States Department of Agriculture

Explain autocatalytic ethylene production.

When fruit is picked before it is ripe and sent to grocery stores. It is sprayed with ethylene to induce ripening. It is sprayed to reduce the amount of time customers have to wait for their fruit to ripen.

Cooperative hydrogen bonding can be described as ______.

Where, due to attractive forces, a hydrogen molecule is drawn to two atoms instead of just one.

____ can effect stability of color.

pH

What is the formula to measure vapor pressure?

ratio of free water/total water

What is the formula that expresses total moisture content?

(g) wt water/(g) wt dry food

______ and ______ are found in syrups and cereal products.

Caramels and melanoidins.

_______ are stored in fatty tissue.

Carotenoids

_______ get their name from carrots, and are a result of the presence of a system of conjugated double bonds.

Carotenoids

What is a mschelle formation?

Chemical formation. Heads orient themselves toward non-polar, tails toward polar.

________ is a characteristic of green vegetables and leaves.

Chlorophyll

In many fruits _______ is present until red and yellow ______ take over.

Chlorophyll, carotenoids

What are the two categories that fruit are divided into?

Climacteric and nonclimacteric

Fruit that experience a large spike in ethylene production as they age are called _______ fruit.

Climacteric fruit

An aerobic bacteria that secretes a neurotoxin is ________.

Clostridium Botcolinum

Pigments are susceptible to oxidation, also known as _____.

Color loss

Retort processes are developed so that the food product is cooked enough to reach _______ sterility.

Commercial

An F value is defined as:

D value x 12, therefore F value is 12D. Time needed to destroy 12 orders of magnitude of microorganisms is usually 250-degrees.

One type of starch or carbohydrate with branch points between the 1st and 6th carbon in called _______.

D-galactaric acid

What are the top two ways to process food?

Dehydration and forced acidity

When one whips egg white into a meringue, one is using mechanical force to ______ the protein.

Denature

What is an anaerobic microorganism? Provide an example.

Does not require oxygen for growth and can die when oxygen is present. Example: Yeast.

How do people become infected with E. coli?

Eating undercooked, contaminated ground beef, or drinking unpasteurized milk.

Polyphenol oxidase is an example of an _______ enzyme.

Endogenous

Two categories of enzymes are _______ and _______.

Endogenous and exogenous

_______ produces short chain fatty acids that smell badly.

Enzymatic browning

The condition at which a product neither gains nor loses moisture is known as ______.

Equilibrium relative humidity

The gaseous hormone in fruit that causes ripening is ______.

Ethylene

What are the two types of pigments?

Fat soluble (chlorophylls and carotenoids) and water soluble (flavonoids, betalains, and quinones)

What does FSIS stand for and what larger agency are they a part of?

Food Safety and Ispection Service. Part of the USDA (US Dept. of Agriculture)

What is the FDA?

Food and Drug Administration

_______ implies that our food will be nutritious, appealing, and healthy.

Food quality

How does Listeria Monocytogenes spread?

Found in soil and water, can spread through contaminated vegetables. Listeria is killed by pasteurization and cooking.

Water activity is the water that is______.

Free for chemical reactions to occur

What is another name for a tamper-evident seal?

Freshness indicator

What is ethylene?

Gaseous hormone secreted by fruits and vegetables. Fruits can sense it in their environment.

Heme pigments are found in _______

Meat and fish

Microorganisms that thrive under ambient conditions such as the counter in your kitchen, without refrigeration, are called _____.

Mesophilic

A _______ more fully describes the moisture content of a food and its water activity

Moisture Sorption Isotherm

The pigment in red meat with Fe+++ at its center is called ______.

Myglobin

What are the three "-globins" that effect meat's color?

Myoglobin (purple), oxymyoglobin or "blooming" (bright red), and metmyoglobin (brown.)

Colors of food are the result of ______ or _______

Natural pigments or added dyes

Are microorganisms always bad? Why or why not? Provide examples.

Not always bad. Can be bad such as E. coli in spinach, but can be good like yeast used for producing bread or microorganisms added to yogurt. W/o certain microorganisms would be almost impossible to produce.

Food quality is relatively subjective, while food safety is very ______.

Objective

______ is required for carotenoid synthesis.

Oxygen

What five variables impact food safety?

Oxygen Accessibility, moisture, temperature, pH, and microorganisms.

What are the two different kinds of thermal processing?

Pasteurization and sterilization

What kind of microorganisms can make you sick?

Pathogens

What are the three types of Non-Newtonian flow? Provide examples.

Plastic - Ketchup, Pseudo-plastic - Jello, and Dilutent - cake mix.

Who does Listeria Monocytogenes affect most?

Pregnant women and adults with weak immune systems.

The simplest indication of quality loss in food is _______.

Presence or lack of water

The level of protein organization that makes proteins different and is characterized by the sequence of amino acids is ______.

Primary

______ can also affect pigment stability.

Processing (heat)

All enzymes are _______, but not all _____ are enzymes.

Protein (both answers)

All enzymes are ______.

Proteins

______ contain peptide bonds.

Proteins

Microorganisms that thrive under cold conditions, such as in your refrigerator are called_____

Psychrophilic

Flavanoids give off the color ______.

Purple, like the color found in eggplant.

Rapid respiration can be slowed by _______.

Quick cooling

________ are responsible for the browning of tea/coffee.

Quinones

Glycosides appear _______ in color. (3)

Red, blue, or violet.

There are three types of water in food systems are these are found in two categories. The categories are _____ and _____ water.

Bound and free

What are the four most common food born illnesses?

Camplyobacter, E. coli, salmonella, and listeria monocytogenes.

What are the four most problematic bacteria of food-born illness?

Camplyobacter, Salmonella, E. coli, and listeria monocytogenes.

How many cases reported each year are caused by the four major bacteria?

Camplyobacter: 1 million Salmonella: 40,000 E. coli: 73,000 (61 deaths) Listeria Monocytogenes: 2,500 (500 deaths)

Where does Salmonella live and how is it spread?

In the intestinal tracts of humans and animals. It does not infect humans unless food is contaminated with animal feces.

Viscosity is created by _______.

Internal friction

Viscosity is created by _________.

Internal friction between particles

What is the main advantage of irradiation?

It can be used with gas impermeable/barrier packaging materials.

What happens if a food has a pH below 4.6?

It is almost impossible for pathogens to grow on the food.

What are the characteristics of a thermophilic microorganism?

It likes heat greater than 45 degrees Celsius. Optimal grown range is between 55-65 degrees Celsius.

What are the characteristics of a psychrophilic microorganism?

Like cold temperatures, less than 20-30 degrees Celsius. Optimal growth range is around 10-20 degrees Celsius.

What are the characteristics of a mesophilic microorganism?

Likes medium temperatures, between 20-45 degrees Celsius. Optimal growth range is between 30-40 degrees Celsius. (Most bacteria fall in this range.)

Which bacteria can cause food-born illness and is particularly dangerous for pregnant women?

Listeria monocyogenes

Acid foods have a ____ pH, while basic foods have a high _____.

Low, high

The most reactive amino acid in maillard browning is ______.

Lysine

_______ creates organoleptic compounds that are pleasing.

Maillard Browning

What is transpiration?

The loss of water by fruits or vegetables.

What is respiration?

The oxidation of organic substrates in the cells into smaller molecules.

Define Moisture Sorption Isotherm.

The plot of water content (expressed as mass of water per unit mass of dry material) of a food versus the water activity (Aw) of the food at a constant temperature.

What is the critical control point?

The point where failure of standard operation procedure (SOP) could cause harm to customers and to the business, or even loss of the business itself. Increasing the surface area of food. (Ex/ ground beef has larger surface area than regular cut beef or steak.)

What is turgidity?

The pressure within the cell that produces the crunch of the food.

Describe the retorting process.

The primary way to thermally process foods, steam or water under pressure are used to heat foods. Retorting kills pathogens, but can alter the flavor or texture of some foods.

A D value is defined as:

The value of a specific food at a specific temperature by decreasing temperature by 1 log.

In what ways can proteins differ?

They can differ in chain length, type of amino acids, combination/structure of of the chain. These variables affect what molecules it can bond to.

How are people normally exposed to the Camplobacter bacteria?

Usually by handling raw or undercooked poultry. Birds can carry the bacteria without being affected.

What is VHP and what is it used for?

Vaporized Hydrogen Peroxide, used primarily in the medical device industry now.

What is conduction heating?

Very slow heating process that heats molecule to molecule, moisture expands and bubbles and spatters at the top. Very slow in thicker products, but stirring can help this.

Caramel colors are soluble in ______.

Water

The simplest indication of deterioration is the loss or gain of ______.

Water

Fruits and vegetables have a high _______.

Water Activity