Effect of the polyunsaturated fatty acid composition of beef muscle on theprofile of aroma volatiles

The effect of n-3 polyunsaturated fatty acids (PUFAs) in beef muscle on the composition of the aroma volatiles produced during cooking was measured. T he meat was obtained from groups of steers fed different supplementary fats : (i) a palm-oil-based control; (ii) bruised whole linseed, which increased muscle levels of a-linolenic (C18:3 n-3) and eicosapentaenoic acid (EPA, C 20:5 n-3); (iii) fish oil, which increased EPA and docosahexaenoic acid (C2 2:6 n-3); (iv) equal quantities of linseed and fish oil. Higher levels of l ipid oxidation products were found in the aroma extracts of all of the stea ks with increased PUFA content, after cooking. In particular, n-alkanals, 2 -alkenals, 1-alkanols, and alkylfurans were increased up to 4-fold. Most of these compounds were derived from the autoxidation of the more abundant mo no- and di-unsaturated fatty acids during cooking, and such autoxidation ap peared to be promoted by increased levels of PUFAs.