Cottonseed Oil Industry Development

The raw materials for the manufacture of soap, the alkali salts of saturated and unsaturated C10-C20 carboxylic acids, are natural fats and fatty oils, especially tallow oil and other animal fats (lard), coconut oil, palm kernel oil, peanut oil, and even olive oil. In addition, the tall oil fatty acids, which are obtained in the kraft pulping process, are used for soap production. A typical formulation of fats for the manufacture of soap contains 80-90% tallow oil and 10-20% coconut oil [2]. For the manufacture of soft soaps, the potassium salts of fatty acids are used, as are linseed oil, soybean oil, and cottonseed oil acids. High-quality soap can only be produced by high-quality fats, independent of the soap being produced by saponification of the natural fat with caustic soda solution or by neutralization of distilled fatty acids, obtained by hydrolysis of fats, with soda or caustic soda solutions. Fatty acids produced by paraffin wax oxidation are of inferior quality due to a high content of unwanted byproducts. Therefore in industrially developed countries these fatty acids are not used for the manufacture of soap. This now seems to be true as well for the developing countries. 

M. L. Meara and E. H. Steiner, Studies on the Fatty Acid Composition and the Crystallizing Behavior of Some of the Major Components, to Obtain Fundamental Information That Will Contribute to the Development ofimroved Edible Products and Hence to Expanded Utilization of Cottonseed Oil, British Food Manufacturing Industries Research Association, Leatherhead, Surrey, U.K., 1966. 

These oilseeds have been developed over the past two decades. These oils are very low in linolenic acid (except high oleic canola). All of these oils can be used for industrial frying without hydrogenation. Fatty acid compositions of these oils are listed in Table 6. These oils are in hmited supply and they are expensive. Com oil, cottonseed oil, and palmolein have been included along with the others for comparison. 

The principal seeds are peanuts (10,400,000 tons), cottonseed (13,-200,000 tons), and soybeans (18,900,000 tons). In the United States, the cottonseed and soybeans are sources of edible vegetable oil for production of cooking oils, shortenings, and oleomargarine. The oil-free residue of the vegetable oil industry is used as a livestock feed, and a small quantity of soybean meal is used in the manufacture of adhesives. Peanuts are used primarily as foods in the United States. Traditionally in areas of major production, except the United States, the oilseeds have been used as livestock feeds and exported to Europe. However, in recent years vegetable oil industries, similar to those in the United States and Europe, have been developed in other countries, particularly in India and South America. 

The development of a characteristic, objectionable, beany, grassy, and hay-like flavor in soybean oil, commonly known as reversion flavor, is a classic problem of the food industry. Soybean oil tends to develop this objectionable flavor when its peroxide value is still as low as a few meq/kg, whereas other vegetable oils, such as cottonseed, com, and sunflower, do not (15, 51). Smouse and Chang (52) identified 71 compounds in the volatiles of a typical reverted-but-not-rancid soybean oil. They reported that 2-pentylfuran formed from the autoxidation of linoleic acid, which is the major fatty acid of soybean oil, and contributes significantly to the beany and grassy flavor of soybean oil. Other compounds identified in the reverted soybean oil also have fatty acids as their precursors. For example, the green bean flavor is caused by c/i-3-hexenal, which is formed by the autoxidation of linolenic acid that usually constitutes 2-11% in soybean oil. Linoleic acid oxidized to l-octen-3-ol, which is characterized by its mushroom-like flavor (53). 

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