From waste to therapeutics: Extraction methodologies and biological properties of bioactive compounds from fruit and vegetable waste

Agriculture-based food byproducts cause enormous environmental stress and a market value loss of 132 billion euros per year. The most wasted product groups in Europe are fruits, vegetables, and cereals. However, food byproducts often contain even more bioactive compounds than edible parts; for example, phenolic compounds and flavonoids are generally stored in seeds and peels. Recent evidence suggests that agricultural waste has therapeutic properties, ranging from antiaging and skin hydration activity to anti-inflammatory, wound healing, or anticancer effects. This review performed a detailed literature search on the therapeutic potential of fruit and vegetable waste via PubMed. It provides a comprehensive review and suggests novel uses and rationalized approaches, with the final aim of providing a practical guide to conducting further experiments in the field. The types of bioactive compounds and their abundance in agricultural waste are initially discussed. Variables affecting the extraction yield, such as the effect of sample pretreatment, the choice of the most appropriate solvent, and different solvent extraction methodologies, are then explored. The therapeutic properties and molecular mechanisms are finally critically discussed.