Fatty acid profile, meat quality and flavour acceptability of beef from double-muscled Piemontese young bulls fed ground flaxseed

This study was designed to assess the effects of dietary flaxseed on the proximate composition, fatty acid profile, lipid oxidation, colour and flavour of the longissimus thoracis muscle of double-muscled Piemontese young bulls. Compared to a control diet, the flaxseed diet had no significant effect on the moisture, protein or ether extract content. Flaxseed modified the fatty acid composition of beef. A more than doubled n-3 polyunsaturated fatty acids (PUFA) content (from 21.1 to 46.7 g / kg of total fatty acids – TFA – in control and flaxseed beef, respectively; p < 0.001) and a lowered n-6 / n-3 PUFA ratio (13.13 versus 5.60; p < 0.001) were observed. The total trans-octadecadienoic acids were also increased by flaxseed (7.8 vs 12.1 g / kg TFA; p = 0.001). The total saturated fatty acids (SFA), monounsaturated fatty acids and PUFA contents, as well as the PUFA / SFA ratio, remained unaffected by the treatment. Lipid oxidation stability tended to be negatively affected by flaxseed (p = 0.096). Such a negative effect was more pronounced as the ageing period advanced. The malondialdehyde content was  0.72 mg MDA / kg meat, and was therefore below the threshold values for rancidity. Meat colour was not influenced by dietary treatment. The inclusion of flaxseed in the diet increased beef flavour intensity perceived by consumers and did not negatively affect flavour acceptability. Properly combining the choice of animal breed and diet allows a slight improvement of the nutritional value of meat for human consumption.