Characterization and quantification of bioactive compounds and antioxidant activity in three different varieties of mango (Mangifera indica L.) peel from the Ecuadorian region using HPLC-UV/VIS and UPLC-PDA

Mango peel is gaining recognition for its nutritional and functional value. This by-product shows variable composition depending on different factors such as variety, stage maturity, and geographic site of production. This work sought to evaluate mango peel composition, bioactive compound content, antioxidant activity, and carotenoid and phenolic profiles for the three most commercial varieties of the equatorial region using UV–Vis spectroscopy, HPLC, and UPLC. Significant differences (p < 0.05) were found between all varieties regarding the content of bioactive compounds. Total phenolic, flavonoid, and carotenoid content ranged from 2930 to 6624 mg GAE/100 g, 502–795 mg CE/100 g, and 3.7–5.7 mg/100 g, respectively. A high positive correlation (r = 0.961) between the phenolic content and ABTS radical-scavenging activity was found for all samples. β-Carotene and lutein were identified and quantified, the samples of cvs. Haden and Kent showed the highest β-carotene content (8 mg/100 g). Gallic acid and rutin were identified in all samples, whereas mangiferin had the highest amount (314 mg/100 g) in cv. Tommy Atkins. The results suggest that mango peel has bioactive compounds with significant antioxidant properties, which can be used as functional ingredients in different industrial products.