Effects of Rosa roxburghii Tratt Aqueous Extract on Protein and Lipid Oxidation of Minced Yak Meat during Storage

The objective of this study was to investigate the effect of Rosa roxburghii Tratt aqueous extract (RRTAE) on protein and lipid oxidation of minced yak meat during storage. Compared with the blank control and positive control of 0.02% butylated hydroxy toluene (BHT), 0.02%, 0.10%, and 0.20% RRTAE were added to minced yak meat. The color, pH, thiobarbituric acid reactive substances (TBARS) value, fluorescent compounds (organic phase δ For, aqueous phase δ Faq), conjugated diolefins (CD) value, carbonyl content, surface hydrophobicity, tryptophan content, dimertyrosine content, and sensory quality of minced yak meat in each group were evaluated on the day 1, 3, 6 and 9 during the storage. The results showed that added 0.10% or 0.20% RRTAE in the minced yak meat could significantly reduce the pH (P<0.05), and 0.02% RRTAE had similar effectiveness comparing with the positive control. RRTAE improved sensory quality, significantly inhibited the decrease of a^* and b^* values (P<0.05), but impaired to the L^* value. Addition of 0.02% RRTAE significantly lowered the TBARS value and dimertyrosine content (P<0.05), and this effect strengthened with the elevation of RRTAE level. Adding 0.20% RRTAE in minced yak meat also significantly reduced the δ Faq, carbonyl content, surface hydrophobicity, and tryptophan fluorescence value (P<0.05). The results suggest that RRTAE can improve the physico-chemical properties of minced yak meat during storage, and may be a potential antioxidant in minced meat storage.