Combined Effects of Different Freezing and Thawing Rates on Meat Quality Characteristics of Aged Lamb Loins

The objective of this study was to determine the combined effects of different freezing and thawing rates on the quality characteristics of aged lamb loins. A total of 105 lamb loins at 1 d postmortem were vacuum-packaged and aged for 2w kat −1.5°C. The loin samples were randomly assigned to 7 treatments, comprising 2 freezing (fast and slow) and 3 thawing rates (−1.5°C, 4°C, and 15°C), along with non-frozen (aged-only) control. Different freezing/thawing rates showed no influence on pH, shear force values, and color parameters of the aged lamb loins (P > 0.05). Fast freezing significantly decreased expressible moisture of the loins compared to slow freezing counterpart, regardless of thawing rates (P < 0.05). A significant interactive effect of freezing and thawing rates was found, where the slow freezing by fast thawing combination resulted in considerable increases in cooking loss. In contrast, fast freezing by fast thawing had a cook loss similar to never-frozen (aged only) control (P > 0.05). These findings suggest that fast freezing of previously aged meat will minimize the amount of moisture loss and thus improve quality attributes of the aged/frozen meat products, irrespective of thawing rates.