Fatty Acid Compositions of Lipids from Adipose Tissues and Muscular Tissue of Pork Carcasses and Their Differences and Correlations

Abstract

The present study was performed with a total of 139 pork carcasses to elucidate the differences and correlation between the fatty acid compositions of adipose tissue lipids and muscle lipids. This included the possibility of readily estimating (with a significantly high correlation coefficient) the fatty acid composition of muscle lipids from adipose tissue lipids. The animals were raised under different conditions in the southern Kyushu area and slaughtered at about 105kg live weight. Their adipose tissues (the outer layer of backfat, OBF; the inner layer of backfat, IBF; perirenal fat, PF and intermuscular fat, IMF) and muscle (M. longissimus thoracis, MLT) were excised and analyzed for their fatty acid compositions.
The percentage concentrations of each of the main fatty acids (palmitic acid, 16:0; stearic acid, 18:0; oleic acid, 18:1; linoleic acid, 18:2) varied among the tissue lipids evaluated. However, those between OBF, IBF and PF were significantly different from each other. The simple correlation coefficient values for the percentage concentrations of main fatty acids between the adipose tissue lipids tended to decrease in the order of (between OBF and IBF)>(between IMF and either OBF or IBF)>(between IMF and PF)>(between PF and either OBF or IBF). This suggests that the effects of extrinsic factors such as feeding conditions are most remarkably reflected in the differences in fatty acid compositions between PF and either OBF or IBF, whereas the respective intrinsic differences in the main fatty acids between OBF and IBF are unlikely to be affected by extrinsic factors. Between the adipose tissue lipids and muscle lipids simple correlation coefficients of their main fatty acids were found to be reduced and varied to a considerable extent. Although the values obtained were significant, they were very low depending upon the kind of fatty acid, particularly for both 18:0 and 18:1. The results demonstrated that there was considerable difficulty in estimating the fatty acid composition of muscle lipids from that for any adipose tissue lipids.