A. I. Glushenkova, N. T. Ul'chenko, M. Talipova, Kh. S. Mukhamedova, N. P. Bekker, and I. Tolibaev UDC 547.916:665.33The class and fatty-acid compositions of the total lipids and phospholipids and the types of triacylglycerols of rice bran oil have been studied. It has been shown that the main lipid class consists of the triacylglycerols; in them the 16:0, 18:1, and 18:2 acids predominate. The main phospholipids are the PCs, PIs, and PEs. The predominating TAGs are the trisaturated and the monosaturated-diunsaturated types, which are present in equal amounts.In the processing of rice grain, a considerable amount of bran is formed that contains 10-14% of protein and is therefore used at the present time mainly in the mixed-feed industry [1]. At the same time, it contains 13-15% of lipids possessing a high biological activity: they improve the carbohydrate metabolism, promote hair growth, and oppose the development of microorganisms [2]. In addition, rice bran contains about 40% of essential fatty acids.However, rice bran also contains a very active hydrolytic enzyme that hydrolyzes the oil, increasing its content of free fatty acids (FFAs) and mono-and diacylglycerols (MAGs and DAGs). This leads to sharp falls in the yield and in the quality of the refined oil, which is used as a foodstuff. With the aim of retaining the native nature of the lipids, therefore, the enzymes have been inactivated before their extraction.We have studied rice bran provided by the Tashkent rice factory. To inactivate the enzymes, the bran was treated either with a steam-water mixture or with a solution of sodium hydroxide. Hexane and chloroform-methanol (2:1) were used as solvents. The yield of hexane extract amounted to 13.2%. The acidity of the oil was 15 %, while without preliminary treatment of the bran it amounted to 61.1 mg KOH [3].To determine the composition of the lipids, the oil was separated into individual factions by CC on silica gel in solvent systems 1-6. The fractions obtained were checked in a thin layer of silica gel in systems 5 and 7. Fractions containing two or more classes of lipids were additionally separated by PTLC in the same systems. The lipids were identified on the basis of their migrational characteristics, by comparison with model specimens, and by the use of qualitative reactions for epoxide rings with picric acid and for steroids with 50% H2SO4.-Their composition is given in Table 1.The main components of the oil were triacylglycerols and FFAs. In addition, incompletely acylated glycerols (monoand diacylglycerols) were detected.The compositions of the total fatty acids of the TAGs and of the fatty acids present in the 2-position of the TAGs were determined ( Table 2). The main acids were the 16:0, 18:1, and 18:2 types.The localization of the acids in the TAGs was determined by Coleman's method [4] and it was established that 90.3 % of their sn-2 positions were occupied by unsaturated acids, which agrees with literature information for plant TAGs and is traditional. The position-species composition of the...