Valorisation of an extract from olive oil waste as a natural antioxidant for reducing meat waste resulting from oxidative processes

Abstract

Spain is the biggest olive oil producer in the world what means that this area is especially affected by olive mill waste pollution. The main system used for extracting olive oil is the continuous two-phase centrifugation system, which generates olive wet cake waste. This wastage has disposal problems due to its phytotoxicity and high moisture content, so strategies for its use and revalorization are needed. One of these strategies is the extraction of bioactive compounds, as is the case of polyphenols present in the waste, which could be used as natural antioxidants in food.

This study evaluated the effect of adding an olive waste extract (100, 200 or 400 mg gallic acid equivalents/kg muscle), as a possible natural polyphenol-rich antioxidant on the stability of lamb meat patties enriched with omega-3 fatty acids, and stored in high-oxygen modified atmosphere packs for up to 9 days at 4 °C. Addition of the extract delayed meat discolouration, lipid oxidation (p ≤ 0.001) and protein carbonylation (p ≤ 0.001), and increased loss of thiol groups (p ≤ 0.05) relative to controls. Fish odour (p ≤ 0.01) and flavour (p ≤ 0.05) were lower and odd odour and flavour (p ≤ 0.001) higher in patties with added the extract compared to controls, but the overall liking score was not affected. The addition of the extract resulted in acceptable lamb meat patties (in terms of oxidation) after 6 days of storage, while patties without extract did not.

The results pointed out the potential for using olive waste extracts as natural antioxidants in meat products. With this strategy, the olive oil industry would encourage to follow an eco-friendlier olive oil production chain obtaining marketable products from the wastes generated. At the same time, the shelf-life (in terms of oxidation process) of the lamb patties would be increased reducing food wastes at the point-of-sale and at consumer level, which is especially important in a high perishable food such as minced meat products, and reducing the environmental impact that food waste causes along the food supply chain.