Sustainable Recovery of Antioxidant Amphiphilic and Lipophilic Bioactives from Avocado By-Products via Green Extraction for Food and Cosmetic Applications

The global avocado industry generates substantial by-product waste, yet these residues remain an underexploited source of health-promoting bioactives. This study explores the sustainable extraction, quantification, and functional evaluation of antioxidant amphiphilic (TAC) and lipophilic (TLC) compounds from avocado (Persea americana) by-products using green, solvent-efficient extraction. The overarching goal is to valorize agri-food waste streams into high-value ingredients for food supplements and cosmetics.

Organically grown domestic (Greek) avocado peels and seeds were subjected to a green extraction and fractionation process to separately obtain the avocado by-products’ extracted TLC and TAC, according to EU regulations. Quantitative analyses of total phenolic content (TPC) and total carotenoid content (TCC), as well as antioxidant activity (DPPH, ABTS, and FRAP), were performed using UV–Vis spectroscopy. ATR–FTIR spectroscopy was used to structurally characterize TAC bioactives, identifying functional groups associated with phenolics, flavonoids, polar lipids, and carotenoids. TAC extracts exhibited higher TPC and superior antioxidant capacity across all assays in comparison to the TLC. Despite relatively modest absolute phenolic and carotenoid concentrations compared to the literature, the extracts retained potent bioactivity, indicating selective enrichment of functional compounds. UV–Vis spectral peaks (240 nm, 310 nm) confirmed the presence of conjugated systems, suggesting potential for anti-UV photo-protective cosmetic applications. ATR–FTIR analysis further identified key amphiphilic constituents, including simple phenolics, flavonoids, polyphenols, carotenoids, and polar lipids.

TAC extracts were successfully integrated into plant-based jelly prototypes as functional food supplements. Antioxidant stability was retained for 15 days under refrigeration, though shelf-life limitations due to moisture and microbial growth highlight the need for preservative strategies.

This work demonstrates a circular bioeconomy approach to food waste valorization, with significant implications for sustainable innovation in functional foods and clean-label cosmetics.