Evolution of the fatty acid composition and oxidative stability of Merino lamb meat stored under different modified atmospheres

The effect of four different gas mixtures on the evolution of the fatty acid composition of neutral lipids and polar lipids, and oxidative stability of Merino fresh Iamb meat was studied. Merino fresh lamb meat was packed under four different atmospheres (Atmosphere 1: Air; Atmosphere 2: 70% O-2 + 30% CO2; Atmosphere 3: 80% O-2 + 20% CO2; and Atmosphere 4: 30% CO2 + 69.6% Ar + 0.4% CO) and stored under refrigeration (3 +/- 1 degrees C) for 12 days. Time of storage only affected the proportions of saturated fatty acids of neutral lipids (P<0.05). There were no significant differences among gas mixtures for the fatty acid profile of neutral and polar lipids during storage (P>0.05). Malondialdehyde and hexanal concentrations were higher for the atmospheres with the highest proportion of oxygen (Atmospheres 2 and 3) indicating lower oxidative stability. The atmosphere consisting of 30% CO2 + 69.6% Ar + 0.4% CO is recommended, due to a higher oxidative stability of meat during refrigerated storage.