(a) State two reasons why food needs to be preserved. [2] (b) Name three different methods of food preservation. [3] (c) Explain how freezing helps to prese...

(a) State two reasons why food needs to be preserved. [2] One mark each (max 2): - To make food last longer and prevent waste (1) - To prevent the growth of bacteria and other micro-organisms that cause food spoilage (1) - To make food available out of season (1) - To allow food to be transported over long distances (1) (b) Name three methods of food preservation. [3] One mark each (max 3): - Freezing (1) - Canning (1) - Drying/dehydration (1) - Smoking (1) - Pickling (using vinegar) (1) - Salting (1) - Pasteurisation (1) - Vacuum packing (1) - Irradiation (1) (c) Explain how freezing preserves food. [3] One mark for each valid point (max 3): - Freezing lowers the temperature of the food to minus 18 degrees Celsius or below (1) - At this temperature, bacteria cannot grow or multiply (1) - The water in the food turns to ice, so bacteria cannot use it to grow (1) - Freezing does not kill all bacteria; they become inactive and can start growing again when food is thawed (1) (d) Describe two rules for freezing food at home. [4] Two marks per rule (max 4): - Food should be cooled completely before placing it in the freezer (1), because putting hot food in the freezer raises the temperature and could affect other frozen foods (1). - Food should be wrapped or placed in airtight containers (1) to prevent freezer burn and to stop flavours and smells from transferring between foods (1). - Food should be labelled with the name and date (1) so that it can be used within the recommended storage time (1).