Effect of vacuum-packaged frozen storage, after cooking, on the phospholipids of Hereford and Bison

Changes in the neutral lipid (NL), phospholipid (PL) and their fatty acid (FA) profiles in lean samples of cooked and cooked, vacuum-packaged, frozen (28 days) Hereford and Bison L. dorsi muscle were analyzed. Samples from Herefords contained more saturated fatty acids (SFA) in the neutral lipid fraction than Bison. Storage decreased the C_18:2, C_18:3, C_20:1 and C_20:4 content of the NL. Bison samples contained more total PL and phosphatidylethanolamine (PE) than Hereford. Storage decreased the content of the least polar of the PL which were eluted in the solvent front (fraction 1), phosphatidylinositol (PI), phosphatidylserine (PS), PE and sphingomyelin (SPH). In the combined PL fraction, there were no differences in the FA profile of Bison and Hereford. Storage resulted in a decrease in the content of C_18:2, C_20:4, unsaturated fatty acid (UFA) and polyunsaturated fatty acid (PUFA) in the combined PL fraction. In the PE fraction, Bison samples contained more C_20:4 and PUFA than Hereford. Storage had no effect on the FA profile of PE. The LPC fraction of Bison samples contained more saturated SFA, UFA and PUFA than Hereford, and with storage these FA decreased. Cooked frozen storage also decreased SFA, UFA and PUFA in PC/LPE.