Proteins Flashcards
(22 cards)
What is mycoprotein made from?
A fungus and egg whites
Note: an alternative can be made with potato starch
An example is Quorn meat
What is HBV?
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
What is LBV?
Low biological value – plant sources of protein
Gelatine is also LBV
Name three essential amino acids.
Leucine
Tryptophan
Valine
Lysine Phenylalanine Isoleucine Methionine Threonine
Histidine
Arginine in children
Name three classifications of proteins.
Primary and secondary
Animal and vegetable
HBV and LBV
What are proteins used for?
Growth
Repair
Maintenance
A secondary source of energy
What are good protein sources?
Nuts Seeds Poultry Meat Fish Soya Eggs
What can soya be made into? Why?
Soya is a HBV plant source
Soya milk –> tofu
Soya flour –> textured vegetable protein (TVP)
Why are some amino acids essential?
They cannot be made by the body and must be taken via your diet.
What are proteins made from?
23 types of amino acids
CHO + N (nitrogen)
What is protein complementation?
Mixing two or more LBV foods to have a HBV meal that contains all EAAs, though some in smaller amounts.
What is gelatine?
A protein from the connective tissue of animals. Lacks 4 EAAs. Used as a setting agent in food.
Evaluate a vegetarian diet.
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.
What are examples of dry heat and moist heat?
Dry heat:
Grilling
Using oil
Air
Moist heat:
Steaming
Boiling
What is coagulation?
Proteins setting
They denature and lose their structure
Example: egg whites at 62C, yolk at 70C
Describe milk in terms of proteins.
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
Describe flour in terms of proteins.
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.
Describe the function of protein in meat.
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.
What happens when you eat too much protein?
Strain on liver and kidneys.
What happens if you have a protein deficiency?
Slowed growth Hair loss Oedema — excess of fluid swelling in body Weak immune system and more infection Lethargy
How is rennin relevant to milk?
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.
What is the difference between plain and strong flour?
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.
