food science

what are the 3 words to do with carbohydrate science?

caramelisation, dextrinisation and gelatinisation

define caramelisation

the browning of sugar when heated causing a change in flavour and colour.

at what temperature does caramelisation occur

154 degrees Celsius

why is there a change is flavour and colour in caramelisation?

because sucrose is being broken down into simple sugars like glucose and fructose

give 3 examples of caramelisation

creme brûlée, caramel and caramelised onions

define dextrinisation

the break down of starch molecules into smaller sugar molecules (dextrins) when they are exposed to dry heat

give three examples of when dextrinisation occurs

toast, cakes and pastry

define gelatinisation

when starch molecules absorb liquid and expand then they pop which causes the liquid to thicken resulting in a sauce

what temperature do the starch molecules start to expand

60 degrees C

what temperature do the starch molecules burst

80 degrees C

at what temperature is the sauce ready

100 degrees C

what are the 4 words to do with protein science

denaturation, coagulation and foam formation

define denaturation

when chains of amino acids unfold which alters the foods texture

give 3 ways that denaturation can occur

heat, acid and mechanical (whisking)

define coagulation

when kinetic energy transfers into the amino acids causing the denatured protein molecules to join together in small groups and bond together in new ways

define foam formation

adding air into the strands of amino acids

what happens to the amino acids after foam formation

expansion

if the protein is heated after foam formation and expansion, what happens then

the protein strands coagulate and solidify trapping the air bubbles inside

give two examples of foam formation

meringues and marshmallows

what 4 words are to do with fat science

aeration, plasticity, emulsification and shortening

define aeration

when air is added and it gets trapped within the triglyceride

give two examples of aeration

buttercream and cake

define emulsification

a way of combing fat with water

describe how emulsification occurs (refer to hydrophobic and hydrophilic ends)

an emulsifier has a hydrophilic head (water loving) and a hydrophobic tail (oil loving). this gradually introduces the two because its molecules arrange themselves so they prevent the oil and water from seperating.

give one example of emulsification

mayonaise

name an emulsifier (which is found in egg)

lecithin

what is the name of a fat and water after an emulsifier has been added?

emulsion

define plasticity

fats ability to spread and mould under pressure

why does plasticity occur

because triglycerides have different melting points

what has a larger plasticity, spread or butter

spread

define shortening

when fat molecules coat gluten, preventing liquid developing the gluten strands (lengthening)

give two examples of shortening

shortbread and pastry

what does the fat act as when it coats the gluten molecules

a waterproof layer

list the 4 types of raising agent

chemical, mechanical, biological and physical

what is a chemical raising agent

reacts with liquid to produce carbon dioxide

give three examples of chemical raising agents

baking powder, bicarbonate of soda and cream of tartar

what must be present for chemical raising agents to work

liquid

what is a mechanical raising agent

a physical action that combines and traps air causing things to rise and expand when cooking

give three methods of mechanical raising agents

whisking, folding and sieving

what is a biological raising agent

a living micro-organism that converts food into carbon dioxide

what 4 factors are needed for a biological raising agent

food, warmth, moisture and time

what is a physical raising agent

when water in a product evaporates causing it to rise

give one example of when physical raising agents are used

choux pastry