The Peels of Fruits and Vegetables: An Increasingly Recognized Source of Bioactive Compounds for Biomedical Applications

Bio-waste (i.e., peels), the by-products obtained from the processing of fruits and vegetables, represents an outstanding advance in agricultural waste valorization due to phytochemical (bioactive compounds) enrichment and the approach to a bio-circular economy and agronomic systems free of hazardous pesticides (soil remediation). These alternatives, which are environmentally friendly and sustainable, are greatly relevant to food and nutraceuticals based on bioactive compounds extracted mostly from peels. Bioactive compounds are defined as natural chemical compounds that have a positive influence on human health. They can aid in the prevention of chronic disease (cancer and degenerative, intestinal bowel and cardiovascular disease) and other types of disease. The bioactive compounds with these properties belong to the family of polyphenol compounds, which include flavonoids (i.e., flavones, flavanones, and anthocyanins), non-flavonoids (phenolic acids, stilbenes, lignin, coumarins, and tannins), and terpenes (carotenoids, lycopene, phytosterols, and monoterpenes). The extraction of these compounds from the peels of fruits and vegetables has gained increasing interest as a sustainable technology because of the use of safety solvents. Another important issue to highlight is the enormous potential of bioactive compounds, as mentioned above, in the biotechnology of these compounds, particularly in terms of the development of a delivery system targeting the site of action.