Postmortem ageing influences the thawed meat quality of frozen lamb loins

The aim of this study was to determine the effect of postmortem ageing on quality attributes of frozen/thawed lamb loins. The loins (M. Longissimus dorsi; n = 30) were randomly divided into six groups: five frozen treatment groups and the control (4 °C for 120 h). Treatment groups were frozen for 3 weeks and thawed at 4 °C overnight, muscles were preserved at 4 °C until 120 h. Compared to the control, pH values and color of frozen meat declined (P < 0.05) after ageing for 72 h, lower shear force values and higher water loss with earlier freezing were due to extensive degradation of myofibril protein. These results indicated the loins frozen in earlier period could accelerate ageing rate, but impaired meat quality inevitably, freezing between 12 h and 24 h postmortem was a better consideration.