Effect of low dose gamma irradiation on beef quality and fatty acid composition of beef intramuscular lipid.

Eight Chinese Yellow Cattle semitendinous muscles were irradiated using a (60)Co irradiation source (with the dose of 1.13, 2.09, or 3.17kGy) and stored (0 day or 10 days at 7°C) to estimate fatty acids change of neutral lipid (NL), polar lipid (PL) and total lipid (TL) fractions, and the beef quality change. Total saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) increased with irradiation, ratios of MUFA to SFA did not change in TL. Whilst, total polyunsaturated fatty acid (PUFA) reduced with irradiation, which resulted in PUFA to SFA ratio decreased in TL (0 day or 10 days). Purge loss and 2-thiobarbituric acid reactive substances values increased with irradiation (from 0 to 3.17kGy) at 0 day, but these values were lower with irradiation at 10 days. Total bacterial counts decreased proportionally with irradiation dose increasing from 0 to 3.17kGy. It can be concluded that fatty acid profiles in beef changed with irradiation; however, fatty acid profiles did not change much at 3.17kGy compared with 1.13 or 2.09kGy, and the beef quality were most acceptable at the dose of 3.17kGy, thus, low dose of about 3kGy gamma irradiation was recommended to apply in fresh beef preparation.