Question 1: Define the term 'gelatinisation' and explain its importance in cooking starch-based foods such as pasta or sauces.

Answer: Gelatinisation is the process where starch granules absorb water and swell when heated, leading to thickening of the mixture. It is important because it gives structure and texture to foods like pasta and sauces.

Question 2: Describe how the functional property of emulsification is used in making mayonnaise.

Answer: Emulsification involves mixing two liquids that normally do not combine, such as oil and water. In mayonnaise, egg yolk contains lecithin which acts as an emulsifier, stabilising the mixture of oil and vinegar or lemon juice to create a smooth, stable sauce.

Question 3: Identify three ways heat affects the functional properties of proteins in food preparation.

Answer: Heat causes proteins to denature, leading to changes in texture and structure; it coagulates proteins, transforming liquid egg into solid; and it inactivates enzymes that may cause spoilage or undesirable changes.

Question 4: Explain the role of fats in creating a flaky pastry.

Answer: Fats in pastry create layers by coating flour particles, which prevents gluten formation and produces a flaky, tender texture when baked.

Question 5: Describe what happens at a molecular level during the process of caramelisation of sugars.

Answer: Caramelisation involves the thermal decomposition of sugars, where heat causes sugar molecules to break down and form new compounds, resulting in a brown colour and complex flavours.

Question 6: Draw a simple diagram showing the structure of a typical protein molecule. Label the amino acids and peptide bonds.

Answer: A correct sketch should depict a chain of amino acids linked by peptide bonds, with labels indicating amino acids as small units and peptide bonds as connections between them.

Question 7: Sketch a diagram to illustrate the process of coagulation in eggs during cooking. Include the key components involved.

Answer: A correct sketch should show liquid egg transforming into a semi-solid mass, with annotations pointing to proteins (ovalbumin) and the process of heat causing protein denaturation and coagulation.

Question 8: Explain how the functional property of foaming is used in making meringues.

Answer: Foaming involves whipping egg whites to incorporate air, creating a stable foam that expands and solidifies when baked, giving meringues their light and airy texture.

Question 9: Describe the effect of temperature on the functional property of enzymes in food processing.

Answer: Temperature can activate enzymes at optimal levels, speeding up reactions, but excessive heat causes enzyme denaturation, stopping their activity and preventing unwanted changes.

Question 10: Identify two functional properties that are affected by pH levels in food and explain their impact.

Answer: Acidity or alkalinity can influence enzyme activity and protein stability; for example, low pH can denature proteins, while pH affects the solubility and taste of food products.