Impact of washing and freezing on nutritional composition, bioactive compounds, antioxidant activity and microstructure of mango peels

•Mango peels had high contents of fiber, mangiferin, gallic acid and β-carotene.•Washing reduced vitamin C, penta-O-galloyl-β-d-glucose, catechin and lutein.•Freezing effects on mango peels’ composition were assessed for the first time.•Freezing increased and reduced free and bound phenolics, respectively.•Freezing markedly changed mango peels’ microstructure. Mango peels are widely produced and highly perishable. Disinfectant washing and freezing are among the most used methods to preserve foods. However, their impact on products’ properties is conditioned by the foods’ features. This study evaluated for the first time the phytochemical composition, antioxidant activity, and microstructure of mango peels washed with peracetic acid (27 mg/mL for 19 min) and frozen at −20 °C for 30 days. Washing decreased the content of vitamin C (−7%), penta-O-galloyl-β-d-glucose (−23 %), catechin (−30 %), and lutein (−24 %), but the antioxidant activity was preserved. Freezing changed mango peels’ microstructure, increased free phenolic compounds, namely acid gallic (+36 %) and catechin (+51 %), but reduced bound phenolic compounds (−12 % to −87 %), bound phenolic compounds’ antioxidant activity (−51 % to −72 %), and violaxanthin (−51 %). Both methods were considered adequate to conserve mango peels since fiber and the main bioactive compounds (free mangiferin, free gallic acid, and β-carotene) remained unchanged or increased.