Effect of Ethanol Extract from Onion Skin on Color, Lipid and Protein Oxidative Stability of Fresh Beef

Beef slices were dipped in three concentrations(0.5%, 1.0%, 2.0%) of ethanol extract of onion peel(EEOS), and then refrigerated at 4 ℃ for 12 days. The inhibitory effects of EEOS on the color browning, lipid oxidation, protein oxidation and spoilage of beef during refrigerated storage were investigated and compared with control(without any antioxidant) and ascorbic acid(V_C). The results showed that EEOS displayed high phenolic content and strong radical scavenging activity. EEOS addition delayed the rise of pH values, enhanced the color stability, and reduced the metmyoglobin of beef. At the same time, it delayed the oxidation process of lipid and protein. Notably, 2% EEOS effectively reduced thiobarbituric acid reactive substances(TBARS) and protein carbonyl content of beef samples by 56.9% and 17.6% than the control group, respectively. In addition, EEOS could significantly reduce the content of total volatile basic nitrogen(TVB-N) of beef during refrigerated storage(P<0.05). Therefore, the addition of 2% EEOS could inhibit the color browning and the oxidation of fat and protein of beef, which could be used as a natural antioxidant in beef refrigerated storage.