Phenolic content, antioxidant potential, and antimicrobial activities of fruit and vegetable by-product extracts

The use of fruit and vegetable by-products as natural food additives has recently been suggested, due to their richness in polyphenols. The aim of this research study was to determine polyphenolic content and the antioxidative and antimicrobial activities of thirteen fruit and vegetable by-product extracts obtained with three solvent mixtures. The Folin-Ciocalteu method was employed to calculate the total phenolic content (TPC) while total antioxidant capacity (TAC) was assessed with DPPH˙ and ABTS˙+. The highest TPC and TAC values were obtained for the acetonic extracts. Pomegranate peels and hazelnut skins showed the highest values of TPC (212.3 and 166.3 mg GAE/g dw respectively) and TAC. The antimicrobial activity against twelve foodborne pathogens and spoilage microorganisms was evaluated. Pomegranate and apple peels showed the highest inhibition of Staphylococcus aureus and Pseudomonas fluorescens. The results obtained demonstrated that by-products could be used as natural food additives with beneficial health properties and antimicrobial activities.