Influence of sex, liveweight and anatomical location of bovine lipids. 3. Fatty acid composition of the neutral and phospholipid fractions from three muscles.

Abstract

Intramuscular lipid from three bovine muscles (17 steers and 18 heifers) (Terrell et al., 1969) were fractionated into neutral and phospholipid moieties. Gas-liquid chromatography was conducted on each fraction from the triceps brachii (TB), transversus abdominis (TA) and psoas major (PM). With the exception of C18, all other fatty acids differed significantly (P<.01) between fractions. The phospholipid fraction had larger percents of C18:2, C18:3, C22 and C20:4 than the neutral fraction. There was no C22 or C20:4 present in the neutral fraction. Major quantities of C17 were associated with the triglyceride of the neutral fraction, although this fatty acid was present in both fractions. There were more differences in fatty acids due to muscle than either sex or liveweight. With the exception of C15 and C17, all other neutral fraction fatty acids differed (P<.05) among muscles. The neutral fraction from the TB had larger percents of C16:1, C18:1, C18:2 and C18:3, while the PM had larger percents of C14, C16 and C18. Only seven of the phospholipid fraction fatty acids differed among muscles (P<.05). The percents of C18:2, C22 and C20:4 were larger in the phospholipid fraction from the TB than in that from the PM. There were more long-chain unsaturates from both fractions associated with the TB than the PM. Significant sex differences (P<.05) were observed for C18 of the neutral fraction (steers=12.44%; heifers= 11.64%) and for C14 of the phospholipid fraction (steers=1.49%; heifers=1.73%). Those fatty acids different for sex also had significant (P<.05) weight group X sex interactions.