Effects of thermal processing and temperature on the quality, protein oxidation, and structural characteristics of yak meat

The aim of this study was to determine the effects of processing on the quality, protein oxidation, and structural properties of yak meat. The cooking loss, Warner-Bratzler shear force, meat color, texture, thiobarbituric acid reactive substance, total carbonyl content (TCC), total sulfhydryl content (TSC), and structural properties of yak meat under frying, drying, and boiling were measured. The results showed that the cooking loss rate, shear force, L* value, hardness, elasticity, and chewiness of yak meat increased (p < .05) and the a* value decreased (p < .05) with increasing central temperature after processing. Fried yak meat at 80°C had the lowest cooking loss rate of 42.21% and the lowest shear force of 50.86 N, which had better textural characteristics, followed by boiling, while the maximum cooking loss rate, hardness, and shear force were 1.40 times, 1.26 times, and 1.2 times that of frying, respectively. The thiobarbituric acid reactive substance was obtained after decoction and peaked at 1.88 ± 0.04 mmol/mg at 60°C. The highest TCC and the lowest TSC were obtained for dried proteins at 80°C. In addition, as the central temperature increased, the helical structure in the protein secondary structure decreased, the disordered structure increased, the fluorescence intensity of myofibrillar proteins decreased, and protein degradation occurred. It was concluded that dried yak meat had the highest protein oxidation and the worst quality, while fried yak meat had the lowest protein oxidation and the best quality.