A pre-chilling intervention strategy for enhancing frozen quality of cooked lamb: Ultrasonic immersion

Improper pre-chilling prior to freezing often leads to significant quality deterioration, while existing quality preservation strategies overlook the importance of controlling the pre-chilling stage. This study investigated the effects of ultrasonic immersion assisted pre-chilling on the quality and microstructure of cooked lamb with vacuum packaging (VPU) during frozen storage. The results indicated that VPU reduced ice crystal size in lamb by up to 25% and promoted a more uniform ice crystal distribution, thereby decreasing thawing loss and cooking loss by up to 21% and 65%, respectively. LF-NMR analysis further demonstrated that VPU inhibited the conversion of bound and immobilized water into free water, thereby improving the water holding capacity (WHC) of lamb. Moreover, VPU reduced TBARS values by up to 28% and maintained texture stability, as evidenced by a 5.87 times lower coefficient of variation (CV) in hardness throughout the storage period compared with the control group. VPU also better preserved lamb color (maintained the highest a* (3.77) at 30 d) and extended shelf life by 4.29 times. Therefore, this study provides novel insights into addressing the issue of freezing quality deterioration in cooked meat products.