Valorisation of mango peel: Proximate composition, supercritical fluid extraction of carotenoids, and application as an antioxidant additive for an edible oil

Mango peel (MP) is an important by-product of the industrial mango processing, rich in phytochemical compounds. This study optimized the operating parameters of the supercritical CO2 extraction (ScCO2) of carotenoids from MP by means of a Box-Behnken design. The MP was characterized in terms of its proximate composition, and the effects of freeze-drying and air-drying on its total carotenoid content were investigated. The carotenoids profile of the optimal ScCO2 extract was characterized by RP-UHPLC-DAD. This extract was evaluated as natural antioxidant for sunflower oil, using the Rancimat (R) method. MP displayed high contents of crude protein and phenolic compounds. Although freeze-drying prevented the degradation of all-trans-beta-carotene, air-drying was selected for the valorisation strategy. The higher yields of carotenoids were found at 25.0 MPa, 60 degrees C, and 15% w/w ethanol. Under these conditions the MP-extracts protected the sunflower oil against lipid oxidation, which could be regarded as an interesting alternative for MP valorisation. (C) 2019 Elsevier B.V. All rights reserved.