3.3 Food science

• the reasons why food is cooked
• the different methods of heat transfer.

Food is cooked to:

• make food safe to eat
• develop flavours
• improve texture
• improve shelf life
• give variety in the diet.

How preparation and cooking affect the appearance, colour, flavour, texture, smell and overall palatability of food.

How heat is transferred to food through:

• conduction
• convection
• radiation.

For sauce making:

• how conduction and convection work to cook a sauce and the need for agitation (S6)
• how radiation works using the grill for a range of foods such as vegetables, meat, fish or alternatives such as halloumi, seeds and nuts, to char, toast and grill (S4).

Selection of appropriate preparation, cooking methods and times to achieve desired characteristics.

• how the selection of appropriate preparation and cooking methods can conserve or modify nutritive value or improve palatability:
  • water based: steaming, boiling, simmering, blanching, poaching, braising
  • dry methods: baking, roasting, grilling, dry frying
  • fat based: shallow frying, stir fry
• how preparation and cooking affect the appearance, colour, flavour, texture, smell and overall palatability of food eg the use of marinades to denature protein.

• Using the oven for baking, roasting, braising, casseroles and/or tagines (S4).
• Dry heat and fat based methods using the hob; dry frying, shallow frying and stir frying (S6).
• Use of the microwave oven (S5).
• Water, dry heat and fat based cooking methods using the hob – to conserve nutritive value eg steaming, stir frying (S6).
• General practical skills – judge and modify sensory properties – awareness of the effect of preparation and cooking on the sensory characteristics of food – appearance, colour, flavour, texture, taste and season adding herbs, spices etc. Use browning and glazing to change texture and flavour. Improve aesthetic qualities of foods by garnishing and decorating (S1).
• The use of marinades to tenderise and flavour meats and alternatives (S9).
• The boiling of vegetables to alter texture (S6).

• protein denaturation
• protein coagulation
• gluten formation
• foam formation.

• the scientific principles underlying these processes when preparing and cooking food
• the working characteristics, functional and chemical properties of proteins.

• Demonstrate how acids denature protein and marinades add flavour and moisture when preparing vegetables, meat, fish and alternatives (S9).
• Setting of egg mixtures eg in quiche (S12).
• Gluten formation – pasta making using a pasta machine, bread making using a bread machine (S5 and S10).
• The use of marinades to tenderise and flavour meats and alternatives (S9).
• Whisking eggs to produce a gas-in-liquid foam eg whisked sponge.

• gelatinisation
• dextrinisation
• caramelisation.

• the scientific principles underlying these processes when preparing and cooking food
• the working characteristics, functional and chemical properties of carbohydrates.

• Make a blended white sauce showing starch gelatinisation such as either a roux or all-in-one blended sauce, infused sauce, velouté or béchamel to demonstrate how liquid/starch ratios affect viscosity (S8).
• Demonstrate how conduction and convection work to cook the sauce and the need for agitation.
• Caramelisation of vegetables (S6).
• Dextrinisation eg browning of bread when baking (S4).

• shortening
• aeration
• plasticity
• emulsification.

• the scientific principles underlying these processes when preparing and cooking food
• the working characteristics, functional and chemical properties of fats and oils.

• Use of fats/oils to demonstrate these processes.
• Shortening and plasticity, eg pastry making (S10).
• Aeration eg using the creaming method with a food mixer for a cake (S1, S4, S5 and S11).
• Make an emulsion sauce such as a salad dressing, mayonnaise or hollandaise (S8).

• enzymic browning
• oxidation.

the scientific principles underlying these processes when preparing and cooking food.

• When preparing fresh fruits such as apples and pears, preventing enzymic browning by using lemon juice (S2) and (S3).
• Oxidation eg preventing water soluble vitamin loss when preparing and cooking vegetables (S3) and (S6).

• chemical (baking powder, bicarbonate of soda, self-raising flours which produce carbon dioxide)
• mechanical (whisking, beating, folding, sieving, creaming and rubbing in – all incorporate air into the mixture)
• steam is produced when the water in any moist mixture reaches boiling point
• biological (yeast).

• the scientific principles underlying these processes when preparing and cooking food
• the working characteristics, functional and chemical properties of raising agents.

• Using chemical raising agents such as self-raising flour and baking powder (S11).
• Use steam in a mixture to raise choux pastry or batter.
• Use egg as a raising agent to:
  • create a gas-in-liquid foam
  • whisk egg whites
  • whisking savoury roulade.
• Yeast in bread making.