Thermal stabilization of banana peels for the preparation of soluble and insoluble dietary fiber

A stabilizing process is required to obtain a stable raw material for producing high-quality food ingredients like soluble (SDF) and insoluble dietary fiber (IDF) from perishable banana peels (Musa acuminata). Therefore, suitable blanching conditions were identified to prevent enzymatic browning while preserving compositional and physicochemical properties. Besides, the impact of ripening degree, hot-air drying at 60 °C, and blanching on banana peel powders (BPP), dietary fiber concentrates (DFC), SDF, and IDF fractions after acidic extraction were studied. The best blanching conditions were achieved after 15 min at 90 °C, resulting in complete polyphenol oxidase inactivation, increased SDF content, and improved water-holding (WHC) and oil-binding capacity (OBC), while antioxidant capacity and total phenolic content remained unaffected. As ripening progressed, impurities in BPP and DFC were significantly reduced (up to 94 % less starch), resulting in a lower yield but higher purity of the SDF fraction (+197 % GalA content). Hot-air drying maintained fiber quality, while enhancing the extractability of the IDF fraction (+9 % yield) and the purity of SDF, reaching 54.5 g GalA/100 g DM. Blanching also increased SDF purity by 52 % by reducing the starch content. Therefore, hot-air drying or blanching is recommended to enhance dietary fiber quality and purity from banana peels.