Red blood cell trans-18:1 isomeric profile correlates with subcutaneous fat and muscle profiles in beef cattle

Due to significant variation in polyunsaturated fatty acid biohydrogenation products in beef it would be useful to determine if levels of trans-18:1 isomers in samples collected ante-mortem are correlated with those collected post-mortem. Beef blood (RBC), subcutaneous fat (SC) and muscle (intramuscular fat; IM) samples were collected from an experiment with dietary vitamin E with/without flaxseed (n=80) and fatty acids analyzed. Across treatments, correlation analysis of total and individual trans-18:1 isomers were performed between tissues. Correlations between SC and IM were highly significant for all individual and total trans-18:1. RBC trans-18:1 were also well correlated with other tissues except for vaccenic acid. Levels of 10t-, 12t- and 13t/14t- were amongst the best correlated between RBC and SC and IM profiles. Levels of 6t/7t/8t-, 9t-, and 15t-18:1 showed significant but lower correlation factors particularly between RBC and SC. These results confirm the possibility of utilizing blood as a non-destructive sample to predict the total and isomeric profile of trans-18:1 in beef.