Effect of different relative humidities on the oil extracted from stored cottonseed

Abstract

Effect of different relative humidities (room, 10%, 46% and 97% R. H.) on the oil extracted from cottonseed stored for one year was studied. The oil extracted from recent non-stored cottonseed was used as a control. Moisture content and oil content in the seed and acid value, peroxide value and percentage gossypol in the oil were determined. The results obtained for the oil extracted from the seed stored under (room, 10% and 46% R. H.) showed a slight difference with the results obtained for the oil extracted from the non-stored conttonseed, while the results of the oil extracted from the seed stored under 97% R. H. showed a considerable difference. Fatty acids composition and unsaturated: saturated fatty acids ratio (U:S) were also evaluated in previous oils. Unsaturated fatty acids were decreased by storage. Accordingly U:S was also decreased. Effect of relative humidity during storage of the cottonseeds on refining and bleaching of the oil was also investigated. The oil of the cottonseed stored under (room, 10% and 46% R. H.) was satisfactorily refined and bleached, givining oils with good colour. While the oil of the cottonseed stored under 97% R. H. could not be satisfactorily refined and bleached. The oil was very dark in colour and did not response to refining and bleaching.