Protein structure and in vitro digestibility of mutton boiled in an enamel cylinder from Xinjiang affected by ultrasound-assisted stewing

In this study, the effects of time (40–80 min), temperature (80–100 ℃) and power (700–900 W, frequency 20 kHz) on the physicochemical properties, sensory quality, food safety and protein digestibility of mutton boiled in an enamel cylinder from Xinjiang (MBECX) were investigated by using ultrasonic-assisted braising technique. The results showed that the ultrasonic temperature higher than 80 ℃ significantly increased the protein digestibility of mutton (P < 0.05). However, prolonged high temperature (100 ℃) treatment damaged the protein network structure and led to water loss, which negatively affected the sensory quality. Optimized ultrasonic conditions (90 ℃, 80 min, 500 W or 100 ℃, 40 min, 900 W) significantly improved the physicochemical properties (P < 0.05), sensory quality and reduced the purine content of the mutton (P < 0.05). The study suggests that appropriate ultrasonic treatment can optimize the process of MBECX and improve product quality and production efficiency.