Colour stability of beef from different Spanish native cattle breeds stored under vacuum and modified atmosphere.

Beef steaks from five Spanish cattle breeds were submitted to three packaging conditions: (a) 15 days under vacuum, (b) 15 days under modified atmosphere (MAP) (60% O(2), 30% CO(2) and 10% N(2)), and (c) 10 days under vacuum plus 5 days more under MAP. CIE L(∗)a(∗)b(∗) coordinates, chroma (C(∗)) and hue (H(∗)), relative concentration of myoglobin, oxymyoglobin and metmyoglobin at the meat surface and sensory evaluation of colour were determined 0, 5, 10 and 15 days after packaging. Beef under MAP showed higher lightness (L(∗)) and hue (H(∗)) and lower redness (a(∗)) and chroma (C(∗)) than beef under vacuum. Colour of beef under MAP was not acceptable after 15 days of storage, due to the high metmyoglobin concentration. Yellowness (b(∗)) was the indicator of differences due to ageing and differences in colour between breeds were related to L(∗), a(∗) and H(∗) values. Packaging conditions had a greater effect on beef colour than breed, but breed differences might change with packaging atmosphere. Both packaging and breed are major factors in packaged beef quality.