FN EOY 9

what is PAL

energy used for movement and to do things

energy requirements

vary depending on PAL and BMR

factors that affect dietary energy needs (5 bullet points)

age;
gender;
body size;
level of physical activity (PAL);
genes.

How to maintain body weight

balance energy intake with energy expenditure from activity.

if energy intake exceeds energy output

you will gain weight

if energy intake is less than energy output

you will lose weight

where do u get energy from

carbohydrates
protein
fat

Total energy expenditure =

Digestion+ BMR + PAL

nutritional function of fats (4 bullet points)

• long-term energy storage,

• insulation

• protecting vital organs,

• essential for the absorption of fat soluble vitamins

energy dense

high number of calories for their weight. a lot of fat or sugar and have little moisture content. chocolate, cake, ice cream

number of amino acids

20

number of essential amino acids

8 but 10 for children

High Biological Value (HBV)

Contains all essential amino acids (animal sources and soy beans)

Low Biological Value (LBV)

protein foods that are missing one of more essential amino acids (plant sources)

protein complementation

Combining two LBV proteins in one meal so you can get all the essential amino acids.

examples of protein complementation

beans on toast, hummus and pitta bread

End product of protein digestion

amino acids are absorbed into blood stream

carbohydrates are compounds of

carbon, hydrogen, oxygen

Carbohydrates break down into

glucose

simple carbohydrates

sugars

complex carbohydrates

starches

3 main carbohydrate groups

monosaccharides, disaccharides, polysaccharides

Monosaccharides

glucose, fructose, galactose

Disaccharides

sucrose, lactose, maltose

Polysaccharides

starch

Dietry fibre benefis for faeces (two bullet points)

• absorbs water to make faeces soft and bulky

• easier to pass preventing constipation and haemorrhoids

other dietary fibre benefits

absorbs fat and lowers cholesterol

how much of our diet should be starchy food

a bit over 1/3

intrinsic sugars

Found naturally in fruits and veg cells

extrinsic sugars

all sugars added to food

a diet high in extrinsic sugars (3 bullet points)

• leads to tooth decay

• obesity.

• cause sugar spikes in blood stressing pancreas.

1g of fat = _ calories

9

one molecule of fat

glycerol and 3 fatty acids

saturated fat

no double bonds, solid at room temp, linked to high blood cholesterol > coronary heart disease

monounsaturated fats

one double bond eg olive oil, avocado, nuts

polyunsaturated fats

more than one double bond and include omega 3 and omega 6 fatty acids eg sunflower oil margarine and oily fish

high intakes of dietary fat leads to

weight gain, which increases likelihood of type 2 diabetes and cancer

Vitamin A and example food

helping immune systems natural defence against illness, eggs

vitamin c and example

helps protect cells from damage, peppers

vitamin d + example food

Helps the body absorb calcium + keep bones strong, egg

u

u

what affects micronutrient requirements? (3 bullet points)

age,

gender,

physiological state

why is food cooked (7 bullet points)

• kill pathogenic bacteria

• make food more palatable- improves flavour, texture, appearance

• reduce bulk of food

• make food easier to chew, swallow, digest

• extend shelf life/ preserve food

• hot food good in cold weather

• provide variety in meals

types of heat transference

conduction, convection, radiation

conduction

heat is transferred through direct contact between 2 objects eg hot pan on stove

convection (two bullet points)

• heat transferred through the movement of air or water.

• water/air is heated, becomes less dense, rises , creates a convection current that can transfer heat to food

radiation (2 bullet points)

• heat is transferred through electromagnetic waves

• eg food placed under a grill

proteins (3 bullet points)

• large chains of amino acids

• folded into compact bundles to take up less space

• held together by bonds

denaturation ( 2 bullet points)

• chemical bonds holding proteins together have broken

• chains have unravelled

aeration (3 bullet points)

• as egg whites are whipped proteins denature

• then recombine trapping trapping air bubbles

• more whipping= more stable

gluten formation (two bullet points)

• glutenin + gliadin + water → gluten

• dough kneaded/ mixed- gluten strands align- trap carbon dioxide from fermentation - dough rises

wheat flour contain which proteins

glutenin + gliadin

factors that effect strength of gluten network (3 bullet points)

• amount of protein in flour

• water added

• degree of kneading/mixing

too little gluten formation =

dense heavy bread

too much gluten formation =

tough chewy bread

coagulation

• denatured protein molecules knock into each other bc they r big

• join into large clumps

• trap + hold water in food

shortening (protein version) (3 bullet points)

• low protein flour

• only mixed to form dough not kneaded

• put in fridge, allows short gluten strands to relax

gelatinisation (4 bullet points)

• starch forms suspension in liquid

• 60oC- starch grains swell

• 80oC- swell to 5 x volume + burst thickening mixture

• 100oC- gelatinisation is complete

what happens if you don’t stir mixture while gelatinisation?

• lumps form

• starch grains sink to bottom and burn

plasticity (2 bullet points)

• dont melt at fixed temps instead over range of temps

• allows fats to be shaped + spread

shortening (fats version)

• fat coats grains of flour

• waterproof layer that prevents gluten development

• short gluten molecules formed - crumbly texture

Emulsification (3 bullet points)

• fat + water cannot combine

• using an emulsifier like lecithin in egg yolk means they can

• creates stable emulsion

Emulsifier

• head is hydrophilic

• tail is hydrophobic or lipophilic

faults with pie recipe: pastry had tough texture (3 bullet points)

• might have used strong flour

• kneaded

• both create excess gluten formation

fault with recipe: pastry shrunk ( 2 bullet points)

• stretched pastry into tin-gluten strands stretched the contracted

• didnt let pastry rest before cooking- gluten shrunk

fault with recipe: pastry tasted/texture undercooked (2 bullet points)

• too much water

• didn’t blind bake pastry

fault with recipe: curd is lumpy (2 bullet points)

• Didn’t stir- the flour was not held in suspension- > sunk to bottom + formed lumps

• Added yolks to hot filling therefore they scrambled

fault with recipe: curd is runny (3 bullet points)

• Not reached full gelatinisation at 100oC

• Didn’t add enough flour

• Too much water

fault with recipe: meringue is runny

• Over whisked the egg whites + the protein has broken down + tightens releasing water

• Under whisked - didn’t form foam

• Added sugar too soon before the foam achieved stiff peaks