Changes Occurring in the Proteins as a Result of Processing Groundnuts under Selected Industrial Conditions.

Considerable quantities of groundnuts are being processed in oil-mills in this country and it is reasonable to suppose that the amount will increase in the future.The high oil content ( 4 -5 0 yo) of the decorticated seed makes groundnuts more difficult to process than most high-protein seeds.In particular, the oil is not so easily extracted as from soya andcottonseed (oil content about 20 yo).Much work has been done on cottonseed and soya beans in the United States, where they are major crops.Little work has so far been published on groundnuts in America, and attention in this country has largely concentrated on maximal oil extraction.The very serious shortage of animal protein available for non-human consumption enhances, however, the importance of vegetable sources of protein and makes it essential that wastage or damage of such protein shall be avoided wherever possible.The present investigation was carried out using industrial plant under selected conditions considered commercially feasible, and it is essentially a study of the effects of temperature and humidity on the protein.As a background to this work, a brief outline of typical oil-mill practice may be relevant.The groundnut seeds are usually received in a decorticated state, and it was on material of this type that the present work was done.The raw material is first subjected in steam-heated pots to a slight cooking process lasting I 5-20 min.at a temperature of 90-looo using dry heat.The object of this is to give the nuts mechanical strength for the subsequent treatment which consists of screw-pressing in 'expeller' machines.'These machines consist essentially of a conical steel shaft set with its axis horizontal and bearing a raised steel thread which turns in a conical steel housing.The material, introduced at the base of the cone, is 'wormed' toward the apex and crushed between