Topic 5: Part G

Question 1

Animal proteins

Answer 1

• meat
• milk and dairy
• eggs

Question 2

Meat

Answer 2

Broadly defined, meat includes muscle tissue and organs of beef, veal, lamb, pork, poultry and fish.

Question 3

Red meat has..

Answer 3

negligible carbohydrate content as the glycogen us used up in the continue metallic process after slaughter

Question 4

Major component of red meat are..

Answer 4

water, fat and protein. some minerals/vitamins

Question 5

Poultry tends to have ..

Answer 5

lower fat content and slightly higher protein content per weight than red meat

Question 6

High water content and neutral pH makes meat..

Answer 6

susceptible to spoilage, this can be reduce by curing (salt addition) or drying

Question 7

Other processing of meat includes..

Answer 7

grinding, canning or freezing

Question 8

Meat usually has some ..

Answer 8

visible fat within the muscle (white streaks/drops is muscle) called marbling

Question 9

Presence of fat increases..

Answer 9

juiciness and gives better eating quality

Question 10

Due to health concerns some animals are bread to have ..

Answer 10

leaner meat

Question 11

The toughness of meat is directly related to the ..

Answer 11

amount of collagen it contains. (older animals have accumulated high levels of collagen yield tougher than young meat)

Question 12

The colour of meat is often used to ..

Answer 12

judge freshness and usually wrapped in material the is permeable to oxygen to preserve the red colour

Question 13

Without oxygen beef is normally what color?

Answer 13

blueish-purple. when its not fresh it turns brown

Question 14

Fish flesh is highly ..

Answer 14

perishable because of the high levels of unsaturated fatty acids which can be readily oxidized

Question 15

Fish fat is rich in a chemical called…

Answer 15

trimethylamine oxide (TMAO)

Question 16

After capturing fish, the TMAO is converted into..

Answer 16

trimethylamine (TMA) that is responsible for the ‘fishy’ odour.

Question 17

Milk is a ..

Answer 17

near perfect food, it is an important source of high quality protein, mineral B vitamins and energy but low iron

Question 18

Milk is composed of 2 protein fractions ..

Answer 18

1: casein (80% of total milk protein)
1: whey (20% of milk protein)

Question 19

During manufacture of cheese..

Answer 19

acid or chymosin/rennin (enzymes) is added to coagulate most of the casein proteins while the whey proteins remain in solution.

Question 20

Whey proteins are composed mostly of ..

Answer 20

beta-lactoglobulin and alpha-lactalbumin.

Question 21

Homogenization is used to produce a..

Answer 21

whole milk product and involves a process that decreases the size of fat globules dispersed in milk so they are more optimally dispersed

Question 22

Freezing destroys process of homogenization, hence the fact that when most milk products are frozen and then..

Answer 22

thawed there is some separation of fat and liquid

Question 23

Evaporated milk

Answer 23

Over half of the water (~60%) is evaporated out of the milk prior to canning. In Canada, it is fortified with Vitamins D and C.

Question 24

Sweetened condensed milk

Answer 24

a canned product where approximately half of the water content is evaporated out of the milk prior to canning and to which a high percentage of sugar is added.

Question 25

Cultured/fermented milk

Answer 25

Bacterial cultures added to ferment the lactose into lactic acid, which thickens the consistency. Ex: Buttermilk, kefir, acidophilus milk, sour cream, yogurt

Question 26

Skim milk powder

Answer 26

The water content of the milk is removed, first through the use of a vacuum and then by spray drying. This form of milk can be used in baked goods and can be added to water to reconstitute fluid milk.

Question 27

Ultra high temp (UHT) milk

Answer 27

the milk is heated for approximately 2-6 seconds at 300F to remove all viable microorganisms. i.e., the product is sterile.

Question 28

Eggs have..

Answer 28

2 major parts: white and yolk

Question 29

Eggs contain ..

Answer 29

protein, fat, vitamins, minerals and a small amount of CHO, with the yolk containing the fat and cholesterol and most of the calories (75%), while the white is the more protein-rich portion

Question 30

Major protein of the egg white is ..

Answer 30

ovalbumin.
Also find conalbumin, ovomucoid, lysozyme and avidin.

Question 31

Major proteins of the yolk are..

Answer 31

the lipoproteins: high density lipoproteins (HDL) and 
 low density lipoproteins (LDL)

Question 32

The shell of the egg is..

Answer 32

94% calcium carbonate and has small pores that allow carbon dioxide and water to escape, while allowing oxygen in.

Question 33

Inside the shell of an egg there is a ..

Answer 33

shell membrane and an egg membrane both for protection. A space forms between the two membranes at the rounded end (ie. air cell) as the egg ages.

Question 34

When the egg is freshly laid the ..

Answer 34

shell is completely filled. The air cell is formed by contraction of the contents during cooling and by the loss of moisture. A high-quality egg has only a small air cell.

Question 35

Functional characteristics of eggs

Answer 35

• Emulsification
• Foaming
• Coagulation

Question 36

Emulsification

Answer 36

lipoproteins and phospholipids present in the yolk help to keep fat dispersed in water. Used in mayo, salad dressings, sauces 
(like hollandaise), ice cream and some cakes.

Question 37

Foaming

Answer 37

proteins in the white have a high capacity to form strong protein films that surrounds air bubbles to produce stable foams. The foams can become 6-8X the original volume. Used in soufflés, fluffy omelets, meringues and some cakes (e.g., angel food).

Question 38

Coagulation

Answer 38

egg white proteins can set and form a gel during heating. They can help to bind food mixtures together, such as meat loaf, meat patties and manicotti.

Question 39

Plant proteins can be divided into 4 broad groups based on solubility properties ..

Answer 39

a. Albumins- soluble in water.
b. Globulins- soluble in salt solutions but insoluble in water.
c. Gliadins- soluble in 70-90% alcohol.
d. Glutelins- insoluble in neutral aqueous solutions, saline solutions or alcohol. Can only be solubilized by dilute alkaline solution.

Question 40

Plant protein crops

Answer 40

• cereals

- pulses, nuts and oilseed

Question 41

Cereals

Answer 41

have protein contents no greater than 15-17% (wheat, corn, rye, rice)

Question 42

In wheat the principal proteins are the ..

Answer 42

the gliadin and glutelin fractions, which represent about 80% of the endosperm protein.

Question 43

Gluten is a complex formed from..

Answer 43

gliadins and glutelins following hydration and mixing of wheat flour.

Question 44

The hydrated gluten complex forms a ..

Answer 44

a 3-dimensional viscoelastic network that gives wheat flour its valued dough and bread-making characteristics

Question 45

Pulses are..

Answer 45

beans (e.g., Navy beans, kidney beans, black beans, etc.), peas (e.g., split peas, chickpeas) and lentils.

Question 46

Contain higher protein contents ranging from …

Answer 46

18-45%. (e.g., peas, lentils, beans, soybean, canola, mustard).

Question 47

Pulses, nuts, oilseeds contain

Answer 47

very little gliadin and glutelin. Majority of the proteins are albumins and globulins.

Question 48

Most pulses offer protein of ..

Answer 48

good quality, while being low in fat

Question 49

Legumes include ,,

Answer 49

pulses, soybeans, seeds and peanuts.

Question 50

Nuts are grown on ..

Answer 50

various trees and ground plants. Provide protein, unsaturated fat, fibre, vitamins, minerals and phytochemicals