Trans isomers contents of the fatty acids in meat products. (III) Adipose tissue and intramuscular fat from beef

Abstract

We give the results obtained for the determination of trans fatty acids in subcutaneous and intramuscular fats from different veal carcasses, using gas chromatography. FA composition differs clearly between both tissues, showing mean values of 58.7% SFA, 39.1% MUFA and 2.7% PUFA in the adipose tissue, and of 44.7% SFA, 46.1% MUFA and 9.4% PUFA in the muscle. Trans fatty acid values obtained in muscle and adipose tissue show statistically significant differences (mean values of 7% total trans fatty acids in intramuscular fat and 10.5% in adipose tissue fat). Besides, we observed a clearly different distribution for C 16: 1t, that didn't show these differences, while C 18: 1t showed a similar distribution than total trans fatty acids. Related to the factors that could determine the trans fatty acid contents in veal carcasses, we found that the race showed more differences between groups than the origin of the animal and their commercial category. On the other hand, correlations we found between trans fatty acids and the total of saturated, mono and polyunsaturated fatty acids showed an opposite sign according to the type of tissue (muscular or adipose). Thus, an increase in the trans fatty acid content was associated with a parallel increase of saturated and decrease in polyunsaturated fatty acid contents in the intramuscular fat. On the contrary, an increase of trans fatty acid content in adipose fat was correlated to a decrease of saturated and an increase of mono and polyunsaturated fatty acid contents.