TEST OF PRACTICAL KNOWLEDGE QUESTION (a) Mention three main ways that food can be contaminated. (b) State five thickening agents for sauces.

Answer Details

(a) Three main ways that food can be contaminated

• Physical contamination, where foreign objects such as hair, glass, stones, insects or pieces of packaging fall into the food.
• Chemical contamination, where cleaning agents, pesticides, disinfectants or other chemicals come into contact with the food.
• Biological (bacterial) contamination, where harmful micro-organisms such as bacteria, moulds and viruses are transferred to food from people, pests, dirty equipment or other raw foods (cross-contamination).

(b) Five thickening agents for sauces

• Wheat flour (used in a roux or blended with liquid).
• Cornflour (corn starch).
• Arrowroot.
• Egg yolk (used to thicken and enrich, as in custard sauces).
• Beurre manié (equal parts of flour and butter kneaded together).

Other acceptable agents include ground rice, gelatine and a starch such as potato starch.