Preservatives are used not only for the food items but for various industrial items also to increase their self life. The preservative industry itself is a big industry as preservatives are used in almost every item today.
In earlier times primitive but effective methods were used to preserve the items like keeping the potatoes or yam buried under the soil in the field. Then pickles were kept in oil and sun for long time by our grandmothers and it was one of the effective ways to preserve. In cold countries keeping the meat in open hanging conditions is still very common.
There are two types of preservatives natural and synthetic. The natural preservatives are the materials like salt, sugar, alcohol, vinegar etc. Boiling and then dehydrating is also one natural way to preserve.
Synthetic preservatives are of two types chemical and artificial. Though they are used much in the industry, can cause health problems if taken in more quantities than the stipulated ones as per the regulations.
Some of the synthetic preservatives are sodium benzoate, benzoic acid, sodium nitrite, sulphur dioxide, sodium sorbate, potassium sorbate, vitamin C, BHA (butylated hydroxyanisole), Sulfites, Vitamin E, Butylated hydroxytoluene (BHT), Disodium ethylenediaminetetraacetic acid (EDTA), Polyphosphates, propionic acid and Citric acid.
Whichever preservatives we use we must restrict them to the quantity as prescribed in food regulations in our country. For half cooked parothas, sorbates or propionic acid based preservatives can be used.
Knowledge is power.