Abstract: In this study, we aimed to the effect of dietary selenium supplementation on the antioxidant capacity and quality of mutton during postmortem aging. Forty 18-month-old Erlangshan white cashmere goats in good condition with an average body mass of (41.20 ± 3.34) kg were randomly divided into a control group (fed a basal diet) and a selenium-rich yeast group (fed a basal diet + selenium-rich yeast (0.5 mg/kg)). The feeding experiment lasted for 90 days conducted and the longissimus dorsi muscle was taken after slaughter for the determination of selenium content. Meat quality and antioxidant properties were determined at 0, 24, 48, 72 and 96 h postmortem. The results showed that dietary addition of selenium-rich yeast effectively enriched selenium in goat meat, and significantly reduced the shear force of goat meat during postmortem aging. Feeding selenium-rich yeast had no significant effect on the richness of volatile flavor substances in goat meat during postmortem aging, but it decreased the production rate of various flavor substance, resulting in a significant increase in the contents of 1-octen-3-ol at 96 h and a significant decrease in the contents of 1-heptanol from 0 to 96 h and 1-heptanol and 2-ethylhexanol, nonanal and octanal at 96 h compared with the control group (P < 0.05). Antioxidant enzyme activities were significantly higher in the selenium-rich yeast group than in the control group (P < 0.05); the carbonyl content was significantly lower than that of the control group at 48–96 h (P < 0.05), and the sulfhydryl content was significantly higher than that of the control group (P < 0.05). Additionally, it was shown that the malondialdehyde (MDA) content, an indicator of the degree of fat oxidation, was significantly lower than that of the control group (P < 0.05).

Key words: selenium-rich yeast, postmortem aging, meat quality, volatile flavor substances