Abstract: This study was performed in order to explore the effect of protein oxidation on the rheological and gel properties of mutton batters. Based on a model oxidation system, different degrees of oxidation were applied to mutton. The carbonyl and total sulfhydryl contents of myofibrillar proteins were determined, and the rheological properties, texture properties, gel strength, water-holding capacity and color of mutton batters were analyzed. The results showed that the carbonyl content increased significantly while the total sulfhydryl content decreased significantly with prolonging oxidation time. The shorter the oxidation time, the higher the storage modulus G’ for each frequency. As temperature rose, G’ was changed in three stages: decreasing slowly from 20 to 47 ℃, and then rapidly from 48 to 54 ℃, and finally increasing rapidly from 55 to 75 ℃. G’ gradually increased during the cooling process. Moreover, as the oxidation time was prolonged, the hardness, elasticity, cohesiveness, adhesiveness, chewiness and resilience of mutton batters declined, and the gel strength and water-holding capacity significantly decreased. The values of L* (brightness), a* (redness) and W (whiteness) also decreased with increasing protein oxidation time. This study showed that protein oxidation could lead to the deterioration of the rheological and gel properties of mutton batters, which adversely affects the processing characteristics of mutton.

Key words: protein oxidation, mutton batters, myofibrillar proteins, rheological properties, gelation properties