Abstract

Coconut oil is one of the important edible oils in India, chiefly on the West Coast and in Bengal. Besides the production in the country, India imports annually about 30,000 tons of coconut oil valued at over 4 crores of rupees. Coconut oil is obtained by crushing the dried kernal of the mature coconut known as Copra. Copra is generally prepared by drying the broken nuts (i. e., nuts cut into halves) in the sun and the oil is extracted by crushing the copra in the village Ghani' or in power driven expellers. The major, if not, almost the entire quantity of the copra of commerce is made and oil is extracted during the summer months of February to May as the weather in that period is bright (thus favourable for copra making) and the largest yield of nuts and outturn of copra and oil are obtained during these months. Practically no crushing of copra for oil is done during the rainy season. It, therefore, becomes necessary to store the coconut oil for pretty long periods and as it easily becomes rancid, a proper method of storage has to be found out. The conditions of storage vary widely. Apart from using numerous containers, substances like jaggery are added to the oil. Perkins (1919) has studied the rancidity of Philippine coconut oil and found out that the oil of low initial acidity remained sweet during two years exposure to air and light. He has further stated that the first stage in rancidity is hydrolysis, the rapidity of which varies with initial acidity and seems to be accelerated by the action of air, light and fat soluble enzymes. But no systematic study seems to have been made so far, on the deterioration of the quality of oil under various conditions. Preliminary studies were therefore conducted to study the deterio- ration of the oil, at the Oilseeds Laboratory at Coimbatore.

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