Chapter 6

Question 1

nutrient profile

Answer 1

the different types and quantities of nutrients that a specific food contains

Question 2

what is a nutrient profile dependant on

Answer 2

-the environment in which they were grown/reared
-the length of time they are stored after harvest or slaughter
-the variety/species of plant or animal

Question 3

leaching

Answer 3

the loss of a nutrient from a food by it dissolving in the water it is cooked in

Question 4

denaturation

Answer 4

the bonds between polypeptide chains are broken by heat, pH and mechanical action resulting in unravelling and reshaping of protein molecules

Question 5

coagulation

Answer 5

the interaction of denatured protein molecules with other denatured protein molecules to form solid and gel textures e.g. egg yolk

Question 6

blanching

Answer 6

plunging vegetables into boiling water for a few seconds to inactivate enzymes before freezing them

Question 7

gelatinisation

Answer 7

cooked sauce is cooled down and the starch molecules start to form longer chains and the water molecules stay trapped inside them so the sauce gradually becomes a solid gel or when food containing starch is cooked

Question 8

how does boiling effect the nutrients

Answer 8

-1/2 of vitamin C is damaged
-vitamin B1, B2 and B3 are damaged by heat and dissolve in water
-calcium and sodium dissolves in water
-starch is gelatinised when cooked in a liquid which makes it easier for body to use

Question 9

how does poaching effect the nutrients

Answer 9

-vitamin B1, B2 and B3 and C are damaged by heat and dissolve in water

Question 10

how does baking effect the nutrients

Answer 10

-the high heat used in baking can easily overcook protein and damage B vitamins

Question 11

how does steaming effect the nutrients

Answer 11

the best way of conserving vitamin C as only about 15% is lost as the food does not come in direct contact with the water

Question 12

how does grilling effect the nutrients

Answer 12

the high heat used in roasting will destroy most of vitamin C and some of B vitamins

Question 13

how does stir frying effect the nutrients

Answer 13

-the fat used in stir frying increases the amount of vitamin A the body can absorb from veg
-the heat will damage vitamin C and some B vitamins but as they are only cooked for a short time damage is minimal

Question 14

how does deep fat frying effect the nutrients

Answer 14

-the high heat will damage vitamin C and some vitamin B and can lead to over coagulation of proteins if cooked for too long
-if the oil is not hot enough when the foods are added they will absorb oil which will significantly increase the fat content and energy value

Question 15

how to reduce the effect the damage and loss of nutrients during food storage

Answer 15

-store food away from heat and light
-store food in airtight containers
-store food for as little time as possible

Question 16

how to reduce the effect of damage and loss of nutrients during food preparation

Answer 16

-avoid buying damaged and bruised fruits and veg as some of their nutrients will have been destroyed
-cut, graze, squeeze, chop fruits and vegetables just before cooking and serving to minimise exposure to oxygen
-if possible avoid peeling fruits and veg as many of the nutrients are found just under the skin and will be lost if it is removed

Question 17

how to reduce the effect of damage and loss of nutrients during cooking

Answer 17

-only use a little water
-boil the water first so the foods start to cook quickly
-cook veg for a minimum time so they are just tender
-steaming instead of boiling veg
-serve straight away
-save cooking water and use in gravies
-cook meat and fish for shortest time possible so the protein is tender and not overcooked
-oil that is used for frying should be changed regularly to prevent consumption of harmful chemicals

Question 18

effect on nutrient of freezing

Answer 18

-vitC, B9, B1 lost during blanching
-some lost by leaching when the food is defrosted
-fats will become rancid after prolonged storage due to oxidation reactions
-freezer burns (exposure of food to dehydrating air inside the freezer) will damage protein and cause texture and flavour changes

Question 19

freezing

Answer 19

-between -18 and -24 and food will develop very small ice crystals inside
-when thawed some texture changed may be apparent and there may be some moisture loss
-chemical reactions still happen inside frozen foods but at a slower rate

Question 20

effects on nutrients jamming

Answer 20

high temperatures destroys the ascorbic acid

Question 21

jamming

Answer 21

-chutneys - fruit and veg are cooked with high temperatures with sugar, salt and vinegar to produce a thick pulp which is stored and sealed in jars
-jams - fruits are stewed with water to extract pectin and then boiled to a high temperature with a sugar until setting point is reached and a gel will form on cooling and stored in jars

Question 22

effects on nutrients pickling

Answer 22

b2 may be destroyed by the action of light through clear glass storage jars

Question 23

pickling

Answer 23

prepared vegetables and other foods are stored in sterilised jars to which vinegar is added. The pickles are left to mature
pickled veg becomes crisp in texture
the acid prevents the growth of microbes

Question 24

effects on nutrients drying

Answer 24

vitamin A is destroyed by heat and air
vitamin C and many B vitamins are destroyed by this process

Question 25

drying

Answer 25

water is driven out of foods either by being laid out in the sun or exposed to warm, dry air in a specially designed drier the foods shrivel and dry out as the water evaporates from them - some foods change colour and their flavour becomes more concentrated microbes cannot grow in the dehydrated foods without moisture

Question 26

effects of nutrients salting

Answer 26

sodium content of the food is increased

Question 27

salting

Answer 27

salt is added to foods to remove moisture from microbes by osmosis which destroys them

Question 28

effect on nutrients stability curing

Answer 28

some desaturation of protein

Question 29

curing

Answer 29

exposing foods to wood smoke which adds chemicals to the food that preserve it

Question 30

effects on nutrient stability canning

Answer 30

ascorbic acid and some B vitamins are destroyed by the high heat some foods develop more antioxidants

Question 31

canning

Answer 31

sealing food inside a metal can then subjecting it to high temperature pressure cooking to destroy microbes and form a vacuum so no other microbes can enter the can until it is opened

Question 32

pasteurisation

Answer 32

fresh food is heated very quickly in a heat exchanger then very rapidly cooled it is heat treated to kill pathogenic bacteria and make the milk safe to drink for several days when stored between 0-5

Question 33

eg pasteurisation

Answer 33

milk, cream, yoghurt

Question 34

effect on nutrient stability pasteurisation

Answer 34

-pasteurisation of milk does not significantly affect the nutrients it contains -there may be some loss of vitamin C in pasteurised fruit juice

Question 35

ultra heat treatment (uht)

Answer 35

ultra heat treatment involves heating food very quickly in a heat exchanged then rapidly cooling it inside special multi-layered storage packs there are completely sealed so that the food can be stored, un-opened and at ambient temperature for several months once opened UHT foods must be stored in a refrigerator and consumed within a few days

Question 36

egs uts

Answer 36

baby foods, sauces, custards

Question 37

effects on nutrient stability uht

Answer 37

milk - no significant loss some vit c may be lost

Question 38

aseptic processing

Answer 38

sterilised liquid foods are packaged and sealed in containers that have been separately sterilised the products do not need to be refrigerated until open

Question 39

vacuum packing

Answer 39

foods are packaged into non-permeable heavy gauge plastic film/containers and all the air is removed to form a tight seal and vacuum around the food this prevents the growth of microorganisms and slows down oxidative reactions

Question 40

modified atmosphere packaging (MAP)

Answer 40

the internal atmosphere of a food package can be modified to remove air and replace it with an inert gas e.g. nitrogen this limits the microbial growth and ensures food stays fresher for longer

Question 41

cook chill

Answer 41

cooked food is rapidly chilled in a blast chiller placed in sealed containers and stored under controlled temperatures for up to 5 days e.g whole or part ready meals

Question 42

antioxidants

Answer 42

chemicals that are frequently added to processed foods to improve their stability and extend their life they can be used as a marketing device to health-conscious consumers bind to free radicals

Question 43

how to antioxidants extend the life of processed foods

Answer 43

-preventing fat soluble vitamins and fat from going rancid -preventing enzymic browning in cut/peeled foods -extending the shelf life of some food products

Question 44

fortification

Answer 44

the addition of nutrients to a food product either to increase the amounts of the nutrients naturally present in it or to add other nutrients that don't naturally occur in it

Question 45

fortifications by law

Answer 45

-vegetable fat spreads = A and D -wheat flour = iron, thiamine, niacin and calcium -wheat flour = folic acid

Question 46

what are ways that nutrients can be added to foods

Answer 46

-enrichment = the addition of nutrients that would naturally occur in food -restoration = the addition of a nutrient to restore natural quantity expected in food -standardisation = addition of a nutrient to a consistent level to compensate for the variations

Question 47

cholesterol lowering food products

Answer 47

natural substances called sterols and stanolds found in plants are added to food products e.g. veg fat spreads, yoghurts and yoghurt drinks during manufacture