Comparative Solubility of Protein in Cottonseed Flakes Extracted by Hexane and by Ethanol

The solvent commonly used in the United States for the extraction of vegetable oils is a petroleum fraction consisting mainly of hexane. Experimental work has been done in this country on the extraction by ethanol of soybean oil by Beckel and associates (1) and of cottonseed and other oils by Rao and associates (4, 5). Ethanol appears promising for use in Asian countries such as India and China largely because it is more readily available than commercial hexane (6). The ethanol extracted cottonseed meal has a lower gossypol content than the hexane extracted meal and for that reason is preferable. However, it is known that ethanol may coagulate some proteins, thus reducing their solubility in water and in aqueous solutions. Because of this relation of solubility and the nutritional value of the protein, determinations of the solubilities of meals produced by the extraction of cottonseed with ethanol and meals produced by the extraction with commercial hexane were made