Effect of gas stunning and modified-atmosphere packaging on the quality of meat from Spanish Manchego light lamb

The aim of the present study was to evaluate the effect of different stunning methods (using two different CO2 concentrations and exposure times) and modified atmosphere packaging systems (MA-O2: 70 O2 + 30 CO2 vs MA-CO: 69.3% N2 + 30% CO2 + 0.7% CO) on the meat quality of Manchego Spanish male light lambs (n = 50). One electrically stunned control group was used. The type of stunning affected pH value, meat tenderness and water losses (P < 0.05) but did not modify most of the colour coordinates or the lipid oxidation level. Furthermore the modified atmosphere with a low CO level (MA-CO) promoted more tender meat with higher oxidative stability than the high-oxygen packed meat (MA-O2). Most likely both the CO2 gas concentration and the exposure time are relevant in the evolution of meat quality from light lambs stunned with different gas stunning systems. In addition, the use of a low CO level to pack lamb meat permits to remove the oxygen from the pack, which improves meat tenderness and the oxidative stability.