functional properties of food

Question 1

protein

denaturation

Answer 1

• the physical alterations which occurs in a protein when it is subjected to unusual environment circumstances
• the hydrogen bonds break apart
• done through whisking, beating, mixing, temperature
  e.g. eggs turning into souffles

Question 2

protein

coagulation

Answer 2

Coagulation occurs after denaturation. It is a physical change in a protein food which results in a gel or elastic solid
e.g. custard, cooked egg

Question 3

protein

foaming

Answer 3

• process of incorporating air into food products, increasing its volume
• creates a light, airy texture
• the fats enables more air to go into the products
  e.g. sifting flour in baked goods

Question 4

protein

gelation

Answer 4

• process of gel formation
• goes from a liquid to solid
• drops of fluid gets trapped in coagulated proteins to which to heat aids this process
• once cooled, the gel is formed with the droplets stuck inside
  e.g. jelly

Question 5

protein

browning

Answer 5

enzymatic browning
- light coloured fruits (apples, bananas) go brown when their flesh is exposed to air
- this is because enzymes causes the oxygen to react with the substances on the flesh

myoglobin browning
- when blood protein in meats are heated, casuing it to denature and changing colour from pink to brown
- when fresh meat is exposed to the air/or ages, the oxygen causes the meat to brown as it changes the iron to myoglobin

maillard reaction
- occurs when the denatured proteins recombine with the sugars present under the presence of dry heat
e.g. toasred marshmallows

Question 6

carbohydrates

dextrinisation

Answer 6

• starch becomes exposed to dry heat which causes the breakdown of starch to dextrin resulting in a change of colour
• only occurs on the surface of foods as the moisture inside stops the temperature becoming hot enough to brown
  e.g. toasted bread

Question 7

carbohydrates

caramelisation

Answer 7

• when sugars or food with high sugar content are heated above melting point and undergo physical change
• becomes a golden brown caramel
  e.g. honey, onions carrots

Question 8

carbohydrates

crystalisation

Answer 8

• the result of cooling a highly saturated solution where solid crystals form

e.g. toffee, fondant

Question 8

carbohydrates

gelatinisation

Answer 8

• starch granules form a suspension in cold water
• when heated in the presence of water, the granules swell and thicken causing the formation of gel
• this is bursts and absorbs the water
  e.g. rice, porridge

Question 9

lipid

emulsification

Answer 9

• when oil and water mixes and joins together in an emulsion
• could be temporary or permanent emulsion
  e.g. temporary: vingear and oil, permanent: yolk and oil