16. Answer in detail II

 

 
Food spoilage may be defined as any change that causes humanchange that causes planchange that causes foodchange that causes animal unfit for human consumption. The enzymes catalysed chemical reactions result in the degradation of food quality, such as bad taste and smell, deterioration, and loss of powerloss of nutrientsloss of energyloss of vitamins.

 

  

Fishes and meat have high levels of polyunsaturated amino acidspolyunsaturated fatty acidssaturated fatty acids unsaturated fatty acids that undergo oxidation cause bad smell when exposed to air or light. This process is called rancidity.

 

  

Apples and some fruits turn brown because of a chemical reaction with oxygen in the air. This chemical reaction is called oxidationbrowningreductionrancidity.

The cells of apples, fruits and other vegetables contain an enzyme called polyphenol lipasespolyphenol maltasepolyphenol oxidasepolyphenol amylase or tyrosinase; when coming in contact with oxygen catalyses a biochemical reaction of plants, phenolic compounds to brown pigments known as melanins.