Nutritional and Phytochemical Profiling of Fruit and Vegetable Peels for Identification as a Potential Nutraceutical Source

Fruit and vegetable (FV) peels have rich nutritional and phytochemical composition, but is influenced by various environmental factors. For effective valorization and incorporation in product development, the selection of an appropriate peel is essential. Nutritional, phytochemical, and antinutritional profiles of twenty FV peels, viz. mango, orange, mosambi, pomegranate, papaya, pineapple, sapota, banana, muskmelon, watermelon rind, banana flower bract, beetroot, bottle gourd, onion, potato, tomato, cauliflower stem, banana stem, cucumber, and ridge gourd was assessed to identify the peels with similar characteristics. The peels were found to be rich source of carbohydrates (93.4% in banana peel), Iron (mango peel - 1072.7 µg/kg), potassium (banana peel-4253.72 µg/kg), and sodium (cauliflower stem - 16858.67 µg/kg). DPPH radical scavenging activity of the cauliflower stem was 95.37%. Total phenol content was highest in pomegranate peel (141.05 mg GAE/g), flavonoids (30.92 mg QE/g), and anthocyanins (196.01 mg C3G/g) in banana flower bract, respectively. Antinutrients viz., tannins were high in mango peel (571.6 mg TAE/g), phytate in beetroot peel (60.1 mg PAE/g), and alkaloids in pomegranate peel (4.7%). Principal Component Analysis and Hierarchical Cluster Analysis were undertaken to find the speciality and similarity between peels. Mango peel (cluster) FP1 was rich in crude fiber, minerals (Ca, Fe, Mn, Ni, Co), phytochemicals (TPC, TFC, TCC), and antinutrients (alkaloids, tannins), whereas banana flower bract (Cluster VP1) with fat, ash, minerals (K, Mg), and phytochemicals (TPC, TFC, TAC). The results demonstrate that assessed peels have a rich nutritional profile, making these a sustainable source of nutrients suitable for fortification and functional food formulations.