Different green extraction technologies for soluble dietary fibre extraction from orange by-product

Abstract

The aim of this work was to extract soluble dietary fibre from orange by-product, by testing four different green (non-contaminant, solvent free) extraction technologies: hot water (HW), extrusion + hot water (EHW), jet cooker (JC) and jet cooker + hot water (JCHW). Starting from orange pomace, the treatments were assayed and sample was separated in soluble and insoluble fractions. The processing and analysis of the soluble fraction was continued, through subsequent spray drying until obtaining a soluble fibre-enriched powder. Powders were analysed: dietary fibre, sugar profile and bioactive characterisation (total polyphenol content, antioxidant capacity). Through the application of these green technologies, it was possible to obtain a functional ingredient with soluble dietary fibre from orange by-product. EHW was the treatment that yielded the highest amount of soluble dietary fibre, the lowest content of glucose, sucrose and fructose, and the highest polyphenol content and antioxidant capacity.