Abstract:To examine the effects of ultrasound on lamb quality, ultrasonic treatments (at 40 kHz and 100 W for 0, 20, and 40 min) were performed on the semimembranosus muscles of sheep. The physical and chemical properties as well as the myofibrillar protein characteristics of the lamb were measured at 4 ℃ at 0, 2, 12, 24, 72, 120, and 168 h. The results demonstrate that during aging, the quality of lamb meat after the ultrasonic treatment is significantly better than that of the untreated lamb meat which was directly subjected to cold storage (p<0.05). After 168 h, the pH value (5.58), L* value, myofibrillar fragmentation index (69.40), and protein solubility (17.40%) of the lamb meat subjected to 20-min ultrasonic treatment were considerably higher than those of the untreated lamb meat subjected to direct cold storage (p<0.05), whereas the shear force of the former (37.54 N) was remarkably lower than that of the latter (p<0.05). These indicators reveal the improved quality of the ultrasonic-treated lamb meat. In addition, the cooking loss of the semimembranosus muscles from the lamb meat that underwent 40-min treatment (26.23%) was greater than that from lamb meat treated for only 20 min (25.83%). Hence, to reduce the quality loss and energy consumption, ultrasonic treatments for approximately 20 min are recommended. The aging time of semimembranosus muscles from the ultrasonic-treated group was 24 h, which was 48 h shorter than that of muscle from untreated lamb (72 h). Overall, ultrasonic treatments can enhance lamb tenderness and improve meat quality while shortening the aging time.
