Effect of flavonoids from Lycium barbarum leaves on the oxidation of myofibrillar proteins in minced mutton during chilled storage.

Herein, we report the effect of flavonoids from Lycium barbarum leaves (LBLF) on myofibrillar proteins (MP) in minced mutton during chilled storage (4 ± 1 ℃). High performance liquid chromatography (HPLC) analysis showed that the total flavonoid content in LBLF was 322.0 mg/g, of which the rutin content was 297.6 mg/g. The effect of 0.5%, 1.0%, and 1.5% LBLF on the structure and thermodynamic properties of MP in minced mutton was studied systematically. Tyrosine and tryptophan of MP samples treated with LBLF were converted from an exposed state to an embedded state. The interaction between LBLF and MP quenched the internal fluorescence, and improved the thermal stability of MP. The addition of LBLF significantly reduced the carbonyl and sulfhydryl contents of MP (p < 0.05), and decreased the surface hydrophobicity of MP in a dose-dependent manner. Our results indicate that LBLF can combine with free radicals produced by protein oxidation, block the free radical oxidation chain reaction, and inhibit the oxidation of MP. Therefore, LBLF may have great potential as a natural antioxidant in meats and meat products during chilled storage. PRACTICAL APPLICATION: Lycium barbarum is widely distributed in China, especially in Qinghai and Ningxia. The results of this study suggest that flavonoids extracted from L. barbarum leaves may be an effective natural antioxidant for the preservation of meats and meat products.