Mango Peel Phenolics Increase the Storage Stability and Cellular Antioxidant Activity of Carotenoid-Loaded Emulsions

Purpose: To encapsulate β-carotene in oil-in-water emulsions added with mango peel phenolics (MPP), thereby utilizing mango peel as an economical source of natural antioxidants to protect this sensitive compound. Tons of mango peel from its industrial processing must be disposed of properly, thus, alternative applications could minimize these amounts. Methods: MPP were extracted and added to β-carotene-loaded emulsions. Their storage stability, cytotoxicity and cellular antioxidant activity (CAA) were evaluated. Results: Emulsion size ranged from 240 to 260 nm, with a polydispersity index ≈ 0.30 and zeta potential ≈ − 30 mV. The addition of MPP resulted in the lowest particle size (240 nm), increased its antioxidant activity, and preserved the stability of encapsulated β-carotene during storage. Emulsions were not toxic against normal retinal cells (ARPE-19, ≥ 90% cell viability), while CAA was higher when MPP were added into emulsions. Cellular uptake increased ≈ 10% of the loaded emulsions, as evaluated by confocal scanning laser microscopy, as compared to Nile Red in solution. Conclusion: Results suggests that emulsifying bioactive compounds prevents losses during storage and improves cellular uptake. Adding MPP can effectively inhibit oxidation of β-carotene and increase antioxidant activity, making them a natural alternative to replace synthetic antioxidants used in food formulations. Graphical Abstract: (Figure presented.).