Ultrasound-assisted extraction of bioactive phenolics from Marselan and Shiraz grape skins: A step toward circular economy in food and pharmaceutical industry

The growing interest in sustainable food supplements and medicinal agents has prompted research into natural bioactive compounds, particularly those derived from agricultural by-products like grape skins. This study examines the antioxidant, anti-inflammatory, and antimicrobial properties of grape skin extracts of Marselan and Shiraz varieties produced in the Šumadija region of Serbia with a focus on their potential applications in the food industry and pharmacy. Six extracts were obtained by ultrasonic extraction of Marselan and Shiraz grape skin with environmentally friendly solvents (water, ethanol and ethyl acetate). The phenolic profiles of the extracts were examined using HPLC analysis, and antioxidant potential using DPPH and ABTS assays, as well as reducing power. The obtained results indicate that ethyl acetate extracts of Marselan and Shiraz show the best antioxidant potential to according these tests. These findings suggest that these extracts could be a promising source of antioxidants for potential therapeutic applications. Additionally, their good antimicrobial properties indicate that could be valuable sources of bioactive compounds for use in functional foods, nutraceuticals, and food preservatives. Highlights • Ethyl-acetate grape-skin extracts showed promising antioxidative and antimicrobial potential. • Ethyl-acetate grape-skin extracts had highest phenolic content. • HPLC analysis of these extracts showed high concentration of compounds with anti-inflammatory potential. • Adhering to the principles of the circular economy in order to reduce waste in the wine industry.