Valorization of Lampung Province banana peel cultivars: nutritional and functional characterizations for biscuit production and wheat flour substitution

This study investigated the functional and nutritional properties of two banana peel flours from Lampung Province, an underutilized agro-industrial waste, BPF-J (Janten) and BPF-K (Kepok). These flours were evaluated as potential substitutes for wheat flour and other functional foods. The banana peels were treated with anti-browning agents and dried at 50 °C for 18 h. Notable nutritional differences were observed: BPF-J contained higher protein, starch, and soluble dietary fiber in g/100 g (7.04, 49.90, and 6.18, respectively), whereas BPF-K had higher fat content, insoluble dietary fiber, and total dietary fiber in g/100 g (12.26, 44.33, and 47.08, respectively). The phenolic content of BPF-J was comparable to that of BPF-K (50.52 and 49.75 mg GAE/100 g dry weight). The highest mineral contents in BPF-J were Fe, Zn, Mg, and K (mg/kg) at 31.82, 16.00, 105.76, and 3705.9, respectively. Conversely, BPF-K had higher Ca and Mn contents (472.02 and 15.68 mg/kg). BPF-K exhibited a higher water holding capacity owing to its higher dietary fiber content. Both flours exhibited similarities in oil holding capacity and swelling power. BPF-J exhibited higher solubility at 70 °C. The pasting properties revealed distinct differences, with BPF-K demonstrating a lower pasting temperature and higher viscosity. Morphologically, BPF-J contained more exposed starch granules than BPF-K, whereas BPF-K displayed a predominantly fibrous matrix. These flours were tested in biscuit formulations, and the 20% BPF-J biscuits showed the best sensory acceptability. These findings suggest that BPF-J and BPF-K are viable and sustainable options for enhancing functional food products.