7.2 Preservatives

2.1 Analgesics
2.2 Control of microbial diseases
2.3 Antibiotics
2.4 Broad spectrum antibiotics
2.5 Sulpha Drugs
2.6 Antihistamines
2.7 Antiseptics and Disinfectants

3.1 Conditions which a dye must satisfy
3.2 Classification of dyes

4.1 Creams
4.2 Perfumes
4.3 Talcum powder
4.4 Deodorants

7.1 Artificial sweeteners
7.2 Preservatives
7.3 Edible colours

8.1 Soap
8.2 Non-soapy detergent or synthetic detergents

9.1 Solid propellants
9.2 Liquid propellants
9.3 Hybrid propellants

Platability and wholesomeness of many foods reach a peak at harvest time. Often food is most appetizing when it comes form the production lime in the food processin plant.

Undesirable changes occur in flavour, colour, texture and appetite appeal. The food producers use various preservative to delay these changes. The preservative prevent spoilage of food due to microbial growth. The most common preservative used is sodium benzoate, ${C_6}{H_5}COONa.$It is metabolized by conversion to hippuric acid, ${C_6}{H_5}CONHC{H_2}COOH$ which ultimately is excreted in the urine. Salt of propionic acid and sorbic acid are also used as preservatives. Potassium metal bisulphite is used for this preservation of colourless food material such as fruit juice, squashes etc.