Valorization of Wine Lees: Assessment of Antioxidant, Antimicrobial and Enzyme Inhibitory Activity of Wine Lees Extract and Incorporation in Chitosan Films

Abstract

Wine lees, as one of the main by-products of winery wastes, is considered a rich source of bioactive compounds such as polyphenols. Recovery of such bioactive compounds would amplify the valorization of winery by-products, as well as promote their use in cosmetics and health applications. Towards this aim, the objective of this work is the recovery of phenolic compounds from wine lees by ultrasound-assisted extraction. The effect of extraction time, and ethanol content on the extraction yield of total phenolics was investigated, while the phenolic profile of the extract was monitored by GC-MS. Under the optimized conditions, the total phenolic content was calculated at 302.6 mg gallic acid equivalents g− 1 dry extract; the dry extract was investigated for its biological activities, exhibiting excellent antioxidant and antimicrobial activity. Moreover, the extract was found to be a potent inhibitor of tyrosinase, elastase, collagenase, α-glucosidase, and α-amylase with IC50 values of 53.3, 83.5, 82.7, 19.0, and 31.3 µg mL− 1, respectively. Finally, the wine lees dry extract was incorporated into chitosan films, reinforcing the properties of the films, and providing them with excellent antioxidant activity. The results support that wine lees extract exhibits high antioxidant activity and can be used as a highly efficient inhibitor of enzymes with pharmaceutical and health interest. Moreover, the chitosan film enriched with wine lees extract is a promising material with high antioxidant potential and can lead to the development of novel food packaging films in the food industry. Graphical Abstract

Exopolysaccharide Production in Submerged Fermentation of Pleurotus ostreatus under Red and Green Light

“…The absorbance was measured at 734 nm at t0 and t30 in a microplate spectrophotometer (Multiskan Spectrum, Thermo Fisher Scientific, Waltham, MA, USA). The values were expressed as % of antioxidant activity and as trolox equivalents using a Trolox standard curve [35].…”