Question 1: Explain how the gelatinisation of starch affects the texture of a thickened sauce. Include the role of heat and moisture in your answer.

Answer: Gelatinisation occurs when starch granules absorb heat and moisture, swell, and burst, releasing starch molecules. This process thickens the sauce, making it smooth and viscous. Heat is necessary to activate gelatinisation, which usually happens when cooking liquids are heated to around 60-80°C.

Question 2: Describe the process of coagulation in eggs when they are cooked and how it influences the final texture of an omelette.

Answer: Coagulation in eggs occurs when the proteins unfold and form new bonds as they are heated, turning from a liquid to a solid. This process gives the omelette its firm, cohesive texture.

Question 3: Identify two functional properties of fats and explain how these properties benefit baked products.

Answer: Two functional properties of fats are: 1) Tenderising - fats coat gluten strands, reducing gluten development and resulting in tender baked goods. 2) Creaming ability - fats can trap air when beaten with sugar, helping baked items rise and become light and fluffy.

Question 4: Explain how emulsification works in mayonnaise and why it is important for the product’s stability.

Answer: Emulsification in mayonnaise involves dispersing oil into water using an emulsifier like egg yolk, which contains lecithin. This forms a stable emulsion, preventing the oil and water from separating, giving mayonnaise its smooth, creamy texture.

Question 5: Suggest two ways to modify the functional properties of flour to improve the qualities of gluten-free bread.

Answer: To improve gluten-free bread, one could add xanthan gum or guar gum to mimic gluten's elasticity, and incorporate eggs or additional starches like potato or tapioca to improve structure and moisture retention.

Question 6: Draw a flowchart illustrating the process of caramelisation, starting from heating sugar to the formation of caramel. Label key stages.

Answer: The flowchart should show: 1) Heating sugar; 2) Melting; 3) Caramelisation begins as sugar melts and browns; 4) Formation of complex flavour compounds; 5) Resulting in caramel with a rich flavour and brown colour.

Question 7: Describe how the Maillard reaction contributes to the colour and flavour of toasted bread.

Answer: The Maillard reaction occurs when amino acids react with sugars at high heat, producing browning and complex flavors. In toasted bread, this gives a golden-brown colour and enhances the nutty, toasted aroma.

Question 8: Explain why gluten development is important in bread-making and how overworking dough can affect this property.

Answer: Gluten development creates a stretchy, elastic network that traps gases produced during fermentation, allowing the bread to rise. Overworking the dough can cause gluten strands to become too tight, leading to a dense, tough texture.

Question 9: Sketch a diagram of the structure of a protein molecule and label the key components involved in its functional properties.

Answer: The sketch should depict a chain of amino acids linked by peptide bonds, with distinct regions representing the secondary structure (alpha helix or beta sheet) and the overall 3D folding, highlighting the importance of amino acid side chains in functional properties.