Process of Obtaining an Antioxidant Ingredient from Red Grape Pomace var. Tempranillo and Its Application in Fresh and Dry-Cured Meat Products

The wine industry is one of the agri-food sectors that generates the most by-products. Pomace, which consists of seeds, skins, stems, and pulp remaining after grape pressing operations, is the most abundant by-product of this industry. Red grape pomace var. Tempranillo was valorized by the application of high hydrostatic pressure, and the effect of the obtained ingredient was evaluated in meat products. A soft thermal treatment prior to high-hydrostatic-pressure treatment was applied to obtain an ingredient rich in phenolic compounds with antioxidant activity from red grape pomace. These processes resulted in a reduction in microbial loads and a decrease in the activity of the polyphenol oxidase enzyme in the pomace, thus yielding a safe product while preserving the phenolic compounds. The antioxidant activity was also well maintained in the valorized ingredient. This valorization process avoids the use of solvents to extract bioactive compounds and allows the entire by-product to be used in meat products, generating no waste. The application of this bioactive ingredient from red grape pomace was evaluated in fresh meat products (hamburgers) and dry-cured meat products (cured sausages) at levels of 0.5% and 1% (w/w). The effect was compared with a control batch (without the ingredient) and another batch manufactured with synthetic additives (metabisulfite for hamburgers and nitrites for sausages). An antioxidant effect was observed in both meat products, as the lowest levels of lipid oxidation were found in the batches containing the pomace ingredient. Therefore, incorporating the bioactive ingredient from red grape pomace into meat products could serve as a natural antioxidant and improve the shelf life of both fresh and dry-cured meat products.