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

Abstract

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.