Question 1: Explain how starch acts as a thickening agent in sauces and soups. Include the role of heat in this process.

Answer: Starch granules absorb water and swell when heated, causing the mixture to thicken. The heat causes the starch molecules to gelatinise, forming a gel that increases viscosity and provides a smooth texture.

Question 2: Describe the effect of heat on the protein in an egg when making an omelette.

Answer: Heat causes the egg proteins to denature and coagulate, transforming from a liquid to a solid, which helps the omelette hold its shape and gives it a firm texture.

Question 3: Identify two functional properties of fat in baking and explain their importance.

Answer: Fat provides lubrication, making baked goods tender and moist, and it also contributes to aeration when creamed with sugar, helping to produce a light texture.

Question 4: Describe the role of gluten in bread making. How does kneading affect gluten development?

Answer: Gluten forms a network of proteins that gives bread its elasticity and structure. Kneading develops the gluten strands, making the dough stretchable and able to trap gases during fermentation.

Question 5: Sketch a diagram showing the process of gelatinisation of starch. Label the key stages including granule swelling and gel formation.

Answer: A correct sketch should show starch granules initially intact, then swelling as heat is applied, followed by the formation of a gel network as the starch molecules leach out and set upon cooling.

Question 6: Explain how emulsifiers work to stabilise mixtures such as mayonnaise. Mention the role of both water and oil phases.

Answer: Emulsifiers have a hydrophilic head and a hydrophobic tail, which allows them to surround oil droplets and prevent them from coalescing, thus stabilising the mixture of water and oil.

Question 7: Describe the functional property of sugars in baking, particularly during the baking process of cakes.

Answer: Sugars contribute sweetness, tenderise the crumb by tenderising gluten, and help with browning through caramelisation during baking.

Question 8: Draw a flowchart illustrating the process of coagulation of milk proteins when making cheese. Include key steps such as curd formation and whey separation.

Answer: A correct flowchart should depict: Milk with proteins → Addition of rennet or acid → Proteins coagulate to form curds → Curd separates from whey → Curd is processed into cheese.

Question 9: Evaluate how the functional property of pectin is used in making jams and jellies.

Answer: Pectin acts as a gelling agent, forming a network that traps water and sugars, creating a thick, gel-like consistency essential for jams and jellies. Its gelling ability depends on the presence of acid and sugar.

Question 10: Identify and explain one way in which heat affects the Maillard reaction in cooking meat.

Answer: Heat accelerates the Maillard reaction, a chemical process between amino acids and reducing sugars, leading to browning and the development of complex flavours in cooked meat.