Explain how food items are spoiled by chemical reactions?
[3 marks]
[3 marks]
1. Spoilage of food and vegetables:
Food spoilage may be defined as any change that causes food unfit for human consumption. The chemical reactions catalysed by the enzymes result in the degradation of food quality in the form of development of bad tastes and odour, deterioration and loss of nutrients.
Examples
• Rotten eggs develop a bad smell due to formation of hydrogen sulphide gas.
• Decaying of vegetables and fruits due to microbes. [1 mark]
2. Rancidity of fishes and meat:
Fishes and meat containing high levels of poly unsaturated fatty acids undergo oxidation. It causes bad odour when exposed to air or light. This process is called rancidity. [1 mark]
3. Apples and fruits turn brown when cut:
-
Apples and some fruits turn brown due to chemical reaction with oxygen in air. This chemical reaction is called browning. [1 mark]
1. Spoilage of food and vegetables:
Food spoilage may be defined as any change that causes food unfit for human consumption. The chemical reactions catalysed by the enzymes result in the degradation of food quality in the form of development of bad tastes and odour, deterioration and loss of nutrients.
Examples
• Rotten eggs develop a bad smell due to formation of hydrogen sulphide gas.
• Decaying of vegetables and fruits due to microbes. [1 mark]
2. Rancidity of fishes and meat:
Fishes and meat containing high levels of poly unsaturated fatty acids undergo oxidation. It causes bad odour when exposed to air or light. This process is called rancidity. [1 mark]
3. Apples and fruits turn brown when cut:
-
Apples and some fruits turn brown due to chemical reaction with oxygen in air. This chemical reaction is called browning. [1 mark]
