Changes the nature of the food.
Coils of amino acids uncoil.
Red, raw steak -(denaturation)-> Brown Steak -(coagulation)-> cooked, starts losing liquid and becoming rubbery.
Coagulation
Nota:
Coagulation is defined as the transformation of proteins from a liquid state to a solid form. Once proteins are coagulated, they cannot be returned to their liquid state. Coagulation begins around 100°F (38°C), and coagulation is complete between 160°F (71°C) and 180°F (82°C).
Flocculation
Nota:
Liquid leaks from the food.
Gelatinisation
Nota:
When starch and liquid are placed on heat, the starch will break down, H2O will slowly enter the starch and enlarge the (starch) molecules.
Types of starches:
- Corn Starch
- Arrowroot Flour
- Custard Flour
- Wheat Flour
- Rice Flour
Factors which affect it:
- Temperature used
- H2O to starch ratio
- Stirring power and how often
- Other ingrediants
Gelation
Nota:
The process of setting food with gelatin.
Browning Reactions
Caramelisation
Nota:
- Involves sugar.
- Must use low heat as sugar retains heat really well.
- Sugar molecules disintegrate at 170 degrees.
- Boiling Sugar and Water.
- Takes place in air and at the bottom of the saucepan.List of Sugars and their Caramelisation-ability- Fructose Readily- Sucrose Readily- Pentose Well- Dectrose Very hard too
Dextrinisation
Nota:
- Affects starch when in dry conditions.
- Starch molecules applied to dry heat --> break down into smaller ones called dextrins.
- Dextrins have a golden brown colour and a sweetish flavour.
Enzymatic Browning
Nota:
- Occurs is fruits or vegetables have been cut or bruised.
- Natural enzymes come in and decompose substances into compounds this results in a dark colour.
- Cooking and/or lack of air destroys enzymes.
Aeration
Nota:
The incorporation of air into food products.
Mechanical
Nota:
Mechanical techniques:
- Sifting
- Rubbing in fat
- Whisking and beating
- Rolling and folding
- Creaming of fat and sugar
- Addition of liquids
Chemical
Nota:
- Can just put in baking powder or bicarbonate of soda
- etc.
Biological
Nota:
Done by using yeast, which need sugar, warmth and moisture to survive.
Emulsion
Nota:
Emulsion is the product of two items which normally would not be able to combine; but are combined due to an emulsifier.