Eco-friendly extraction and comprehensive analysis of nutritional compositions, mineral profile, bioactive molecules, and antioxidant activity of selected fruit and vegetable peels

Sustainable utilization of fruit and vegetable wastes addresses a key challenge in achieving a circular and resource-efficient food system. This study aimed to valorize 15 selected fruit and vegetable peels by profiling their nutritional and antioxidant contents. The potential of these peels as nutrient- and bioactive-rich resources was evaluated using microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional water bath extraction (WBE) methods. Nutritional analysis focused on moisture, ash, protein, fat, and carbohydrates, while mineral content confirmed the presence of essential macro- and micro-elements. Specifically, carrot peels exhibited the highest β-carotene content (2.45 mg/100 g ), while mango peels had the highest total carotenoids (53.33 mg/100 g ). Phenolics were most abundant in grape peels (21007.56 mg GAE/100 g), and orange peels showed the highest flavonoid content (1750.83 mg CE/100 g). These bioactive components exhibited significant antioxidant activity, with grape peels achieving 90.61% in DPPH assays and 12250.12 mg TE/100 g in FRAP assays. MAE proved most efficient in extracting bioactives, followed by UAE. These findings highlight the effectiveness of modern green extraction technologies in converting waste into valuable resources, supporting sustainable waste management, and maximizing agricultural resource utility.