Title : Valorization of agri-food by-products as a strategy to reduce the ecological footprint of the food system
Abstract:
The valorization of agri-food by-products is increasingly recognized as a key strategy to enhance sustainability and reduce the environmental footprint of the food system. Recent reviews highlight the relevance of recovering bioactive compounds from food waste streams as part of the circular bioeconomy (Mir-Cerdà et al., 2023; Rifna et al., 2023). In this context, the present study examines the antioxidant potential of aqueous extracts obtained from grape, olive, tomato, lemon, red pepper, and pomegranate by-products, comparing them with a commercial rosemary extract (Timón et al., 2024). Water proved to be an efficient and environmentally friendly extraction solvent, enabling the recovery of phenolic compounds, vitamin C, and carotenoids. Antioxidant activity—evaluated through RSA, MQA, and RP—showed strong correlations with phenolic and vitamin C content, while carotenoids displayed weaker associations. Olive, grape, and lemon by-products exhibited the highest antioxidant capacities, in some cases comparable to rosemary. Phenolic profiling revealed distinct compositions across extracts, with compounds such as hydroxytyrosol, 4-hydroxybenzoic acid, oleuropein, rutin, and tyrosol contributing to the observed antioxidant patterns. PCA further demonstrated that phenolic composition and antioxidant mechanisms jointly shape the functional behavior of these extracts. Overall, the findings underscore the suitability of plant by-products as sustainable sources of natural antioxidants for food applications, supporting waste reduction and contributing to a lower ecological footprint within the agri-food sector.
