Effect of winery by-product extracts on oxidative stability, volatile organic compounds and aroma profile of cooked pork model systems during chilled storage

Grape stem and vine-shoot extracts have been studied in cooked pork model system as alternative preservatives to prevent oxidation reactions. After cooking, samples were stored in refrigeration and analyzed at 0, 10 and 20 d. Winery extracts addition (3 g/100 g) preserved better redness loss and reduced lipid and protein oxidation during chilled storage, being more effective than the traditional additive sodium ascorbate. A significant increase of total phenolics content and catechins, and the subsequent greater antioxidant capacity, were observed in samples added with winery extracts, being particularly noticeable in those treated with vine-shoot extract. Furthermore, volatile organic compounds (VOCs) concentration derived from lipid oxidation during chilled storage were lessen inhibited thanks to the extracts addition. Nonanal, some unsaturated aldehydes and octanoic acid showed high odor activity values (OAVs) in control samples after storage, evoking rancid odors. In this sense, winery by-products samples did not exhibit these flavors whereas distinguished pleasant sensorial features described as "herbaceous" or "woody" were found.