Class #8: Eggs, Milk & Cheese Flashcards
Why do eggs work as good binders?
They are high in protein
How much can egg whites increase in volume?
6-8x
True or False: Fresh eggs have thicker egg whites.
True, therefore they whip to create a more stable foam.
Why should you use room temperature eggs when whipping?
There is less surface tension on the eggs.
Why shouldn’t you use a plastic bowl to whip egg whites?
Plastic is porous and holds contaminants easily, copper bowls can actually interact with the egg white to allow air bubbles to expand more.
How does salt affect whipping egg whites?
Decreases stability and volume
True or False: Sugar destabilizes egg white foam.
False, but sugar does inhibit coagulation and should be added at the end.
Why does acid make eggs whip more easily?
Egg proteins are more likely to denature in an acidic environment.
True or false: The yolk makes up half the weight of the egg.
False: 1/3
True or false: The colour of the yolk depends on the pigements in the chickens feed.
True
True or false: The albumen is uniformly thick throughout the egg.
False. The albumen around the yolk is thicker.
True or False: The chalaza is made of twisted albumen.
True
True or false: The egg shell is made of plastic like material.
False, calcium carbonate.
True or false: the smaller the air pocket, the fresher the egg.
True
Why are some eggs brown?
Different breed of hen
Most of the fat in eggs is what kind of fat?
MUFA
How much protein is in 1 large egg?
7g total (4 from white, 3 from yolk)
Why is Fe not bioavaliable in eggs?
It is bound to phosvitin.
What is the dominant protein in eggs?
Ovalbumin-it denatures easily.
Which protein complexes iron?
Conalbumin
Which protein binds riboflavin?
Flavoprotein
Which protein bind biotin?
Avidin
Which protein is resistant to denaturation?
Ovomucoid, inhibits trypsin
What percentage of the yolk is cholesterol?
4-5%
What pigments are present in egg yolk?
Xanthophyll, lycopene, lutein, zeaxanthin
True or false: The germinal disk is darker when the egg has been fertilized.
True
What is codding?
Basically poaching, but with a bowl to hold the egg in the water.
How are eggs graded?
Based on the weight of a dozen eggs.
What is candling?
Holding light up to the egg to see contents.
True or false: Eggs age more in 1 day at room temperature than 1 week in the fridge.
True
True or False: Eggs get contaminated from salmonella from contacting a surface with the bacteria after they are cracked.
False, it comes from chickens that have that bacteria in the ovary or vaginal canal.
Define Milk.
White yellowish liquid secreted from mammary gland to serve as nutrition for new born.
True or False: Milk is an incomplete protein
False.
What nutrients are present in milk?
All B vits, Vit AD, Ca, P, K, Mg,S
True or False: Vit D is fortified in all milks.
True
Which vitamins are fortified in skim and partially skimmed milk?
Vitamin A and D, because they are both fat soluble vits.
Which milk is fortified with vitamin C?
Evaporated milk
What percentage of milk is water?
87.4%
What are the two milk proteins?
Casein & Whey
Which of the two milk proteins is present in a higher amount (80%) in milk?
Casein
What is whey made of?
Lactalbumin and lactoglobulin
Which protein is precipitated by acids or enzymes in cheese making?
Casein
True or False: Milk fat is mostly unsaturated fat.
False, it’s 66% saturated fat.
How is fat present in milk? (in what form)
TG’s surrounded by lipoproteins and cholesterol (casein micelle)
How much energy is in 250ml of whole milk?
150kcal
How many grams of fat are present in 250ml of whole milk?
8g
Which has more fat: buttermilk or 1% milk?
1% has 3g of fat, buttermilk has 2g
True or false: the carbohydrate in milk is mostly lactose.
True
How much lactose is in 250ml of milk?
12g
How is lactose responsible for flavour development in cheeses? (what does it turn into)
Lactic Acid
What is lactose intolerance caused by?
Insufficient lactase on brush border.
True or False: Milk allergies may be related to beta-lactoglobulin
True
True or False: Fermented milk products contain more lactose.
False. Fermented milk products contain less lactose.
What is 1 serving of milk according to CFG?
250ml milk, 125ml evaporated milk, 175g yogurt, or 50g of cheese
Which milk alternative is high in protein?
Pea milk
How many grams of protein are in 250ml of milk?
8g
True or False: Ultra high temp pasteurization means that milk is heated for longer than in regular pasteurization.
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.
What is measured to ensure milk adequacy? (in terms of food safety)
Phosphatase enzyme activity, as well as white blood cell count (high WBC count indicates the cow is fighting some sort of disease)
Describe homogenization
Mechanical process that breaks up fat globules to permanently disperse them in the emulsion. Prevents separation of fat.
True or false: Acidophilis milk is cultured with acid.
False. It is cultured with acidophilis bacteria
True or False: Sour cream is cultured with bacteria.
True
Why is greek yogurt high in protein?
Whey has been drained out, giving a thicker, creamier product.
How much milk is consumed in liquid form?
30%
What moisture content does fresh cheese have?
a. greater than 80%
b. 50-75%
c. 40-50%
d. 30-40%
e. less than 30%
a
What moisture content does soft cheese have?
a. greater than 80%
b. 50-75%
c. 40-50%
d. 30-40%
e. less than 30%
b
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%
c
What moisture content does hard cheese have?
a. greater than 80%
b. 50-75%
c. 40-50%
d. 30-40%
e. less than 30%
d
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%
e
How much cheese does 10lbs of milk make?
1lbs cheese., 9lbs whey
True or False: Casein micelles are negatively charged inside.
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.
Why does coagulation with acid cause the cheese to lack calcium?
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.
True or false: Acid coagulated cheeses can be aged.
False.
True or false: coagulation with enzymes makes tougher cheeses.
True.
How does rennin interact with casein micelles?
It cuts K casein tails, removing the negative charge. This way, casein coagulates and the calcium is retained in the curd.
What is cutting? (curd treatment)
Literally cutting the curd, increasing SA and lowering moisture when strained.
What is pressing? (curd treatment)
curds being compacted into solid mass
How does heating the curd affect the texture of the cheese?
increases evaporation=firmer
What is knitting? (curd treatment)
Curds being melted into a solid mass
What is curing? (cheese)
Aging of cheese in controlled temperature and humidity
What is ripening?(cheese)
Chemical and physical changes in the amino acids and other components of cheese.
What is responsible for flavour development in cheese?
Caseins undergoing proteolysis, and then the AA”s being decarboxylated, transamination, oxidative deamination, and degradation.
What does whey drained from cheese making contain?
Whey protein, lactose, h2o sol vits, minerals.
What can leftover whey be made into?
Whey Cheese, Dry Whey (livestock feed), Modified Whey (ingredient in processed cheese)
What is primost?
Goat/cow cheese where milk sugars are caramelized before curd is formed, (maillard reaction) = sweet, spreadable cheese.
Why does shredding cheese make it melt better?
Increases surface area
True or False: higher fat cheeses melt better.
True
What is oiling off?
When some free fat is released from the cheese and glistens on surface.
What is blistering?
Darkening on the surface of heated cheese. Aged cheeses create larger blisters, while unaged cheese creates smaller, but more blisters.
Why does cheese brown?
Sugar+AA+lactose can all brown.
True or False: Cheese with more calcium phosphate is stretchier
False, it is tougher. But aged cheeses are softer because proteins break down in aging.
