Chemicals in Processing Agricultural Commodities
We know fruits, vegetables, ﬁshes etc. are called agricultural commodities. The process through which agricultural commodities are kept fresh for a long time or be saved from decay by using any chemical substance is called processing of agricultural commodities.
Use of chemical substances has both merits and demerits. Mangoes get spots when the traders transport them from one place to another by buses, trucks or trains. People usually do not want to buy these spotted mangoes. For this reason, unscrupulous traders buy green mangoes and transport them from one place to another. As a result, the mangoes don get spots.
Then the unscrupulous traders apply a liquid solution of calcium carbide on the mangoes to ripen them. Again, acetylene is prepared by adding water to the liquid solution of calcium carbide (CaC2).
Ripening mangoes by carbide mean the process of ripening mangoes by acetylene. Besides, mangoes are ripened by the ethylene gas. Ethylene also has a negative impact on our body.
Chemicals in Preserving Agricultural Commodities
Generally, agricultural commodities are preserved by ice, table salt, Vinegar etc. so that they do not become odorous or do not decay. For example, fishes are preserved by ice and vinegar is used to preserve tomatoes and green mangoes, etc. in containers. Vinegar enters our body with food but it does not harm us. Foods are not preserved by formalin because it is very harmful material for man and animals both. We may even die if formalin enters our body. Hence, we should not be used formalin to preserve foods.
Related: Chemistry in Agriculture and Industries: Limestone, Urea and Ammonium Sulphate
Some Recommended Food Preservatives
The chemical substances which protect food items from bacteria, bad smell, and decay are called food preservatives. Recommended food preservatives are those which do not harm our body and are approved as food preservatives by the World Health Organization. The preservatives which harm our body are called unauthorized food preservatives.
Some recommended food preservatives are sodium Benzoate, benzoic acid, vinegar and solutions of salt and sugar etc. Ethylene, acetylene etc. are unauthorized food preservatives and obviously harmful for our body.
Industrial Disposal and Environment Pollution
Industrial disposals pollute the environment. The country like Bangladesh, tannery, paint and pesticide industries dispose of different kinds of heavy metal such as chromium (Cr), lead (Pb), mercury (Hg), and cadmium (Cd) as industrial efﬂuent. These heavy metals or effluents enter soil and water. They also enter the plants that grow on this soil. When we eat fruits from these plants then the heavy metals also enter our body and damage our kidney and liver. Even they can cause our death too.
Again a huge quantity of caustic soda (NaOH) from soap and detergent factories goes into soil and water. If NaOH goes into the water, the level of alkalinity in water increases. As a result, aquatic animals and plants cannot live in water properly.
References: NCTB Books and Google