Proteins

Question 1

What is mycoprotein made from?

Answer 1

A fungus and egg whites
Note: an alternative can be made with potato starch
An example is Quorn meat

Question 2

What is HBV?

Answer 2

High biological value – all essential amino acids are present in the food
Animal sources (except gelatine) are HBV
Soya, TVC, tofu and mycoprotein are plant HBV sources

Question 3

What is LBV?

Answer 3

Low biological value – plant sources of protein

Gelatine is also LBV

Question 4

Name three essential amino acids.

Answer 4

Leucine
Tryptophan
Valine

Lysine
Phenylalanine
Isoleucine
Methionine
Threonine

Histidine
Arginine in children

Question 5

Name three classifications of proteins.

Answer 5

Primary and secondary
Animal and vegetable
HBV and LBV

Question 6

What are proteins used for?

Answer 6

Growth
Repair
Maintenance
A secondary source of energy

Question 7

What are good protein sources?

Answer 7

Nuts
Seeds
Poultry
Meat
Fish
Soya
Eggs

Question 8

What can soya be made into? Why?

Answer 8

Soya is a HBV plant source
Soya milk –> tofu
Soya flour –> textured vegetable protein (TVP)

Question 9

Why are some amino acids essential?

Answer 9

They cannot be made by the body and must be taken via your diet.

Question 10

What are proteins made from?

Answer 10

23 types of amino acids

CHO + N (nitrogen)

Question 11

What is protein complementation?

Answer 11

Mixing two or more LBV foods to have a HBV meal that contains all EAAs, though some in smaller amounts.

Question 12

What is gelatine?

Answer 12

A protein from the connective tissue of animals. Lacks 4 EAAs. Used as a setting agent in food.

Question 13

Evaluate a vegetarian diet.

Answer 13

More moral and environmentally friendly
Methane gas is not released.
Lower cholesterol.

Difficult to receive all EAAs.
Deficiency in other vitamins.
Reliant on meal planning.

Question 14

What are examples of dry heat and moist heat?

Answer 14

Dry heat:
Grilling
Using oil
Air

Moist heat:
Steaming
Boiling

Question 15

What is coagulation?

Answer 15

Proteins setting
They denature and lose their structure

Example: egg whites at 62C, yolk at 70C

Question 16

Describe milk in terms of proteins.

Answer 16

80% water, 20% proteins.
80% of protein is caseinogen (used in buttons)
20% of protein is lactalbumin
Coagulates by heat. Forms a skin

Allows milk to be boiled over. Water must be trapped to heat more quickly

Question 17

Describe flour in terms of proteins.

Answer 17

Glutenin + gliadin (+ water) –> Gluten strands
Can be kneaded smooth to make strands parallel
Makes dough elastic and provides structure

Ferments and fills with carbon dioxide to rise.

Question 18

Describe the function of protein in meat.

Answer 18

Meat has muscle fibres from actin and myosin.
They shrink and tighten to form tight balls when cooked.
Connective tissue between fibres.

Collagen and elastin make the connective tissue.
Can be broken down, but is difficult to get rid of.

Collagen (+ moist heat for a long time) –> gelatine
Methods include pressure cooking and stewing.

Question 19

What happens when you eat too much protein?

Answer 19

Strain on liver and kidneys.

Question 20

What happens if you have a protein deficiency?

Answer 20

Slowed growth
Hair loss
Oedema — excess of fluid swelling in body
Weak immune system and more infection
Lethargy

Question 21

How is rennin relevant to milk?

Answer 21

Stomach clots caseinogen with rennin.

Rennin is found in lemon juice. Becomes acidic because of harmless bacteria. Bacteria feeds on lactose and it forms lactic acid that coagulates the caseinogen. Curds.

Rennin can be replaced by genetically modified yeast.

Question 22

What is the difference between plain and strong flour?

Answer 22

Plain flour has 7% protein, but strong flour has 14% protein.

Plain flour: cakes/biscuits. Spring-sown. Structure is not necessary or unwanted.
Strong flour: bread, flaky pastry and pasta. Autumn-sown. Structure is desired.