Effects of Mango Peel Addition on the State Diagram and Quality Changes of Ultra-Fine Mango Powder During Storage

Mango (Mangifera indica L. cv. Tainong) peel waste is a promising source of physicochemical and nutritional ingredients for food applications. This study aimed to explore how peel addition affects the storage stability and quality deterioration of ultra-fine mango powders, with the peel powder incorporated into mango-flesh powder at mass fractions of 8%, 16% and 24%. The state diagrams indicated that peel addition significantly lowered the water activity (Aw) and raised the glass transition temperature (Tg) of the powders, improving stability. Physicochemical characters including color, moisture content, Aw, bulk density, angle of repose, reducing sugar, ascorbic acid, β-carotene, total phenols, flavonoids, and antioxidant activity of ultra-fine mango powders incorporated with peel were monitored and modeled during 90 days of storage at 4 °C. The results indicated that peel addition adjusted the initial color and narrowed the color changes of the stored samples, as well as inhibiting moisture adsorption and Aw. The degradation of reducing sugars and β-carotene in ultra-fine mango powders with different peel content followed first-order kinetics, whereas ascorbic acid, total phenol content (TPC), and total flavonoid content (TFC) conformed to second-order models. Peel enrichment dose-dependently increased initial bioactive levels, reduced degradation rates, and extended half-lives (t1/2). After 90 days, TPC and TFC losses dropped from 43.60% and 51.24% (pure powder) to 28.91% and 41.58% with 24% peel addition. Antioxidant activities were improved by peel addition and exhibited a strong positive correlation with TPC and TFC (R2 > 0.94). These results support mango peel as a sustainable functional ingredient for clean-label products and circular economy strategies.