Influence of brown rice in diet on the fatty acid and triglyceride composition of porcine fat

This experiment was conducted to study the effects of brown rice in diet on the properties of porcine fat. Landrace pigs were fed the diets supplemented with brown rice at different levels of restricted feeding. The fat samples used for analysis were obtained from kidney adipose tissues by rendering, and the fatty acid composition of fats were determined by gasliquid chromatography. Then, the fatty acid distributions in pork fat triglycerides were studied by means of pancreatic lipase hydrolysis, and component triglycerides were calculated according to 1, 3-random-2-random distribution theory. As the results obtained from the experiments of feeding and carcass, there was no significant difference among experimental lots, and it was considered that brown rice had about same feed value as compared with corn or barley. The concentrations of myristic, palmitic, stearic, oleic and linolenic acid in diet lipid increased and the concentrations of linoleic and total unsaturated fatty acid decreased as the supplement level of brown rice in diets increased. As the level of supplementation of brown rice in experimental diets increased, the concentration of linoleic acid decreased and the concentrations of palmitoleic and linolenic acid increased in the kidney leaf fats of pigs fed those diets. Distinct variation in fatty acid composition of 2-monoglyderides derived from pork fat triglycerides by means of pancreatic lipase hydrolysis was not found depending upon the difference of diets. But, in the composition of fatty acids located on 1- and 3-position of pork fat triglycerides, concentration of linoleic acid decreased and that of linolenic and oleic acid tended to increased as the supplementation of brown rice in diets increased. So, it was considered that the influence of diet on the fatty acid distribution in pork fat triglycerides were more distinctly appeared on the acyl groups at the 1- and 3-position of triglyceride than at the 2-position. The compositions of triglycerides estimated on pig kidney leaf fats were as follows 12.93% SSS, 38.79% SSU, 2.74% SUS, 8.51% SUU, 30.88% USU, and 12.93% UUU. And, the compositions of these triglycerides were not significantly different among experimental lots, however, it was observed that there were significantly more 1-stearo-2-palmito-3-olein and 1-stearo-2-myristo-3-olein in the fat of pigs fed highly brown rice supplemented diets as compared to that of pigs fed control diet, and that 1, 2-dipalmito-3-linolein or 2-palmi