Effect of lamb age and retail packaging types on the quality of long-term chilled lamb loins.

The objective of this study was to determine the impact of lamb age and packaging types on meat quality. Paired loins (M. longissimus dorsi) were obtained from 36 carcasses that included 4-month-old (New season; NS) and 11-month-old lambs (Old season; OS). The loins were vacuum-stored for eight weeks at -1.5°C. After storage, the loins were cut into subsamples and were randomly assigned to either high-oxygen modified atmosphere packaging (HiOx-MAP) or PVC-overwrapping for further display for 8 days. No differences between the age classes in shear force and drip loss were found (P>0.05). OS loins had significantly higher myoglobin and redness compared with NS loins. HiOx-MAP initially induced a more intense red colour compared with PVC (P<0.05), but resulted in severe discolouration at the end of display regardless of the age class. This observation suggests that the retail packaging type is the dominant factor over the age on lamb colour stability.