Explain the importance of chemicals in food and also explain their types.

(N/A) Chemicals are added to food for $(i)$ their preservation,$(ii)$ enhancing their appeal,and $(iii)$ adding nutritive value to them.
The main categories of food additives are as follows:
$(i)$ Food colours
$(ii)$ Flavours and sweeteners
$(iii)$ Fat emulsifiers and stabilizing agents
$(iv)$ Flour improvers,antistaling agents,and bleaches
$(v)$ Antioxidants
$(vi)$ Preservatives
$(vii)$ Nutritional supplements such as minerals,vitamins,and amino acids.
Except for chemicals of category $(vii)$,none of the above additives have nutritive value. These are added either to increase the shelf life of stored food or for cosmetic purposes.