Class #8: Eggs, Milk & Cheese

Question 1

Why do eggs work as good binders?

Answer 1

They are high in protein

Question 2

How much can egg whites increase in volume?

Answer 2

6-8x

Question 3

True or False: Fresh eggs have thicker egg whites.

Answer 3

True, therefore they whip to create a more stable foam.

Question 4

Why should you use room temperature eggs when whipping?

Answer 4

There is less surface tension on the eggs.

Question 5

Why shouldn’t you use a plastic bowl to whip egg whites?

Answer 5

Plastic is porous and holds contaminants easily, copper bowls can actually interact with the egg white to allow air bubbles to expand more.

Question 6

How does salt affect whipping egg whites?

Answer 6

Decreases stability and volume

Question 7

True or False: Sugar destabilizes egg white foam.

Answer 7

False, but sugar does inhibit coagulation and should be added at the end.

Question 8

Why does acid make eggs whip more easily?

Answer 8

Egg proteins are more likely to denature in an acidic environment.

Question 9

True or false: The yolk makes up half the weight of the egg.

Answer 9

False: 1/3

Question 10

True or false: The colour of the yolk depends on the pigements in the chickens feed.

Answer 10

True

Question 11

True or false: The albumen is uniformly thick throughout the egg.

Answer 11

False. The albumen around the yolk is thicker.

Question 12

True or False: The chalaza is made of twisted albumen.

Answer 12

True

Question 13

True or false: The egg shell is made of plastic like material.

Answer 13

False, calcium carbonate.

Question 14

True or false: the smaller the air pocket, the fresher the egg.

Answer 14

True

Question 15

Why are some eggs brown?

Answer 15

Different breed of hen

Question 16

Most of the fat in eggs is what kind of fat?

Answer 16

MUFA

Question 17

How much protein is in 1 large egg?

Answer 17

7g total (4 from white, 3 from yolk)

Question 18

Why is Fe not bioavaliable in eggs?

Answer 18

It is bound to phosvitin.

Question 19

What is the dominant protein in eggs?

Answer 19

Ovalbumin-it denatures easily.

Question 20

Which protein complexes iron?

Answer 20

Conalbumin

Question 21

Which protein binds riboflavin?

Answer 21

Flavoprotein

Question 22

Which protein bind biotin?

Answer 22

Avidin

Question 23

Which protein is resistant to denaturation?

Answer 23

Ovomucoid, inhibits trypsin

Question 24

What percentage of the yolk is cholesterol?

Answer 24

4-5%

Question 25

What pigments are present in egg yolk?

Answer 25

Xanthophyll, lycopene, lutein, zeaxanthin

Question 26

True or false: The germinal disk is darker when the egg has been fertilized.

Answer 26

True

Question 27

What is codding?

Answer 27

Basically poaching, but with a bowl to hold the egg in the water.

Question 28

How are eggs graded?

Answer 28

Based on the weight of a dozen eggs.

Question 29

What is candling?

Answer 29

Holding light up to the egg to see contents.

Question 30

True or false: Eggs age more in 1 day at room temperature than 1 week in the fridge.

Answer 30

True

Question 31

True or False: Eggs get contaminated from salmonella from contacting a surface with the bacteria after they are cracked.

Answer 31

False, it comes from chickens that have that bacteria in the ovary or vaginal canal.

Question 32

Define Milk.

Answer 32

White yellowish liquid secreted from mammary gland to serve as nutrition for new born.

Question 33

True or False: Milk is an incomplete protein

Answer 33

False.

Question 34

What nutrients are present in milk?

Answer 34

All B vits, Vit AD, Ca, P, K, Mg,S

Question 35

True or False: Vit D is fortified in all milks.

Answer 35

True

Question 36

Which vitamins are fortified in skim and partially skimmed milk?

Answer 36

Vitamin A and D, because they are both fat soluble vits.

Question 37

Which milk is fortified with vitamin C?

Answer 37

Evaporated milk

Question 38

What percentage of milk is water?

Answer 38

87.4%

Question 39

What are the two milk proteins?

Answer 39

Casein & Whey

Question 40

Which of the two milk proteins is present in a higher amount (80%) in milk?

Answer 40

Casein

Question 41

What is whey made of?

Answer 41

Lactalbumin and lactoglobulin

Question 42

Which protein is precipitated by acids or enzymes in cheese making?

Answer 42

Casein

Question 43

True or False: Milk fat is mostly unsaturated fat.

Answer 43

False, it's 66% saturated fat.

Question 44

How is fat present in milk? (in what form)

Answer 44

TG's surrounded by lipoproteins and cholesterol (casein micelle)

Question 45

How much energy is in 250ml of whole milk?

Answer 45

150kcal

Question 46

How many grams of fat are present in 250ml of whole milk?

Answer 46

8g

Question 47

Which has more fat: buttermilk or 1% milk?

Answer 47

1% has 3g of fat, buttermilk has 2g

Question 48

True or false: the carbohydrate in milk is mostly lactose.

Answer 48

True

Question 49

How much lactose is in 250ml of milk?

Answer 49

12g

Question 50

How is lactose responsible for flavour development in cheeses? (what does it turn into)

Answer 50

Lactic Acid

Question 51

What is lactose intolerance caused by?

Answer 51

Insufficient lactase on brush border.

Question 52

True or False: Milk allergies may be related to beta-lactoglobulin

Answer 52

True

Question 53

True or False: Fermented milk products contain more lactose.

Answer 53

False. Fermented milk products contain less lactose.

Question 54

What is 1 serving of milk according to CFG?

Answer 54

250ml milk, 125ml evaporated milk, 175g yogurt, or 50g of cheese

Question 55

Which milk alternative is high in protein?

Answer 55

Pea milk

Question 56

How many grams of protein are in 250ml of milk?

Answer 56

8g

Question 57

True or False: Ultra high temp pasteurization means that milk is heated for longer than in regular pasteurization.

Answer 57

False. Regular milk is heated at a lower temperature (below boiling point) for a longer time. UHT pasteurization means the milk is heated past boiling (138-150C) for 2 seconds.

Question 58

What is measured to ensure milk adequacy? (in terms of food safety)

Answer 58

Phosphatase enzyme activity, as well as white blood cell count (high WBC count indicates the cow is fighting some sort of disease)

Question 59

Describe homogenization

Answer 59

Mechanical process that breaks up fat globules to permanently disperse them in the emulsion. Prevents separation of fat.

Question 60

True or false: Acidophilis milk is cultured with acid.

Answer 60

False. It is cultured with acidophilis bacteria

Question 61

True or False: Sour cream is cultured with bacteria.

Answer 61

True

Question 62

Why is greek yogurt high in protein?

Answer 62

Whey has been drained out, giving a thicker, creamier product.

Question 63

How much milk is consumed in liquid form?

Answer 63

30%

Question 64

What moisture content does fresh cheese have? a. greater than 80% b. 50-75% c. 40-50% d. 30-40% e. less than 30%

Answer 64

a

Question 65

What moisture content does soft cheese have? a. greater than 80% b. 50-75% c. 40-50% d. 30-40% e. less than 30%

Answer 65

b

Question 66

What moisture content does semi-hard cheese have? a. greater than 80% b. 50-75% c. 40-50% d. 30-40% e. less than 30%

Answer 66

c

Question 67

What moisture content does hard cheese have? a. greater than 80% b. 50-75% c. 40-50% d. 30-40% e. less than 30%

Answer 67

d

Question 68

What moisture content does very hard cheese have? a. greater than 80% b. 50-75% c. 40-50% d. 30-40% e. less than 30%

Answer 68

e

Question 69

How much cheese does 10lbs of milk make?

Answer 69

1lbs cheese., 9lbs whey

Question 70

True or False: Casein micelles are negatively charged inside.

Answer 70

False. The K-casein tails sticking out of the micelle is negatively charged, with Ca and P inside the micelle. This is why the micelles repel each other.

Question 71

Why does coagulation with acid cause the cheese to lack calcium?

Answer 71

Calcium in milk exists with casein or as free ions, at pH7, Ca is in the casein micelles, which are broken apart by acid, releasing the Ca into the whey.

Question 72

True or false: Acid coagulated cheeses can be aged.

Answer 72

False.

Question 73

True or false: coagulation with enzymes makes tougher cheeses.

Answer 73

True.

Question 74

How does rennin interact with casein micelles?

Answer 74

It cuts K casein tails, removing the negative charge. This way, casein coagulates and the calcium is retained in the curd.

Question 75

What is cutting? (curd treatment)

Answer 75

Literally cutting the curd, increasing SA and lowering moisture when strained.

Question 76

What is pressing? (curd treatment)

Answer 76

curds being compacted into solid mass

Question 77

How does heating the curd affect the texture of the cheese?

Answer 77

increases evaporation=firmer

Question 78

What is knitting? (curd treatment)

Answer 78

Curds being melted into a solid mass

Question 79

What is curing? (cheese)

Answer 79

Aging of cheese in controlled temperature and humidity

Question 80

What is ripening?(cheese)

Answer 80

Chemical and physical changes in the amino acids and other components of cheese.

Question 81

What is responsible for flavour development in cheese?

Answer 81

Caseins undergoing proteolysis, and then the AA"s being decarboxylated, transamination, oxidative deamination, and degradation.

Question 82

What does whey drained from cheese making contain?

Answer 82

Whey protein, lactose, h2o sol vits, minerals.

Question 83

What can leftover whey be made into?

Answer 83

Whey Cheese, Dry Whey (livestock feed), Modified Whey (ingredient in processed cheese)

Question 84

What is primost?

Answer 84

Goat/cow cheese where milk sugars are caramelized before curd is formed, (maillard reaction) = sweet, spreadable cheese.

Question 85

Why does shredding cheese make it melt better?

Answer 85

Increases surface area

Question 86

True or False: higher fat cheeses melt better.

Answer 86

True

Question 87

What is oiling off?

Answer 87

When some free fat is released from the cheese and glistens on surface.

Question 88

What is blistering?

Answer 88

Darkening on the surface of heated cheese. Aged cheeses create larger blisters, while unaged cheese creates smaller, but more blisters.

Question 89

Why does cheese brown?

Answer 89

Sugar+AA+lactose can all brown.

Question 90

True or False: Cheese with more calcium phosphate is stretchier

Answer 90

False, it is tougher. But aged cheeses are softer because proteins break down in aging.