Dietary Supplementation of Dried Grape Pomace Increases the Amount of Linoleic Acid in Beef, Reduces the Lipid Oxidation and Modifies the Volatile Profile

SIMPLE SUMMARY: The grape pomace is the main solid by-product of the oenological industry, and represents a rich source of potent bioactive compounds. In this study we demonstrated that its inclusion in bovine diet resulted in a significant increase of linoleic acid concentration in meat, a condition which led to a positive increase in the polyunsaturated fatty acid:saturated fatty acids (PUFA:SFA) ratio. Despite the greater predisposition of PUFA to oxidation, an interesting improvement in the oxidative stability of meat was evidenced, presumably as an effect of the antioxidant activity performed by the bioactive compounds of which the grape pomace is rich in. This finding was also confirmed by the analysis of volatile compounds which highlighted a reduction of hexanal in meat samples obtained from animals fed the dietary grape pomace supplementation. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry. ABSTRACT: The aim of this study was to evaluate the effect of dietary supplementation with dried grape pomace on beef quality. Ten Friesian calves were divided into two groups, a control group that received a standard diet, and an experimental group that was administered the dietary supplementation. At the end of the 75 days of the trial, animals were slaughtered, and meat samples analyzed for physical and chemical properties, fatty acids composition, lipid oxidation, volatile compounds, and biogenic amines. The fatty acid profile resulted affected by dietary supplementation, since an increase in concentration of linoleic acid was observed. Furthermore, a reduction of lipid oxidation was found in the same samples. With reference to volatile compounds a reduction of hexanal and an increase of 2-3 octanedione was evidenced, while no effects were induced by diets on the synthesis of biogenic amines. The grape pomace exploitation as a dietary supplement in bovine diet did not have negative effects on the quality of beef and showed the potential to extend shelf life due to marked improvement in oxidative stability. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry.