Diversity of fructo-oligosaccharides, antioxidants, and bioactive components in plantain peel as a function of genotype

Plantains, a widely cultivated fruit crop, generate substantial peel waste, comprising approximately one-third of their total weight. Despite their potential, these peels are often discarded as waste. This study investigated the valorization of plantain peels as a source of functional carbohydrates, particularly fructooligosaccharides (FOS), and explored their phytochemical composition, focusing on phenolic compounds and antioxidant properties. FOS content was evaluated across 40 plantain varieties, ranging from 2.8 to 11.5%, with Lacatum-1, Manoranji Tham, and Nendran (unripe) exhibiting the highest levels. UPLC-QToF-ESI-MS/MS analysis identified 36 phenolic compounds in the peel extract, including chicoric acid, chlorogenic acid, ferulic acid, and p-coumaroyl tyrosine. Major flavonoids included rutin, catechin, myricetin and quercetin derivatives. Significant variations were observed in total phenolic content (TPC) and total flavonoid content (TFC). The highest TFC was recorded in Aayirakai Rasthali and Udayam, while Naadu and Virupakshi exhibited the highest TPC. Antioxidant activity, assessed using DPPH, ABTS, and FRAP assays, revealed IC50 values ranging from 49.3 to 125.7 μg/mL in DPPH, 54.1 to 127.8 μg/mL in ABTS, and 52.5 to 128.3 μg/mL in FRAP. This comprehensive study highlights the potential of plantain peel as a valuable source of functional carbohydrates and bioactive compounds, emphasizing its application in health-promoting and antioxidant-rich products.