Q. Explain Preservation by Preservatives?

Preservatives, as you may already know, belong to a class of food additives that extend shelf life by inhibiting microbial growth, or by minimizing the destructive effects of oxygen, metals, and other factors that may lead to rancidity. Common preservatives include nitrites (used extensively in processed meats), sodium benzoate (often added to soft drinks), sorbic acid (dairy products), calcium and sodium propionates and sorbates (mould inhibitors used in baked goods) and common table salt.

The preservatives generally used in fruit and vegetable products may be broadly classified as class I and class II preservatives.

The class I preservatives are the natural preservatives which are not restricted in any food. Examples of class I preservatives are common salt, sugar, dextrose/glucose syrup, spices, vinegar or acetic acid and honey.

Class II preservatives are the chemical preservatives, which prevent or delay the growth of microorganisms. However, the use of chemical preservatives is limited in foodstuffs.