Characterisation of physicochemical and functional properties of soluble dietary fibre from potato pulp obtained by enzyme-assisted extraction

Abstract

In this study, enzyme-assisted methodology was applied with the aim to optimise the efficiency of soluble dietary fibre (SDF) extraction from potato pulp. The yields of SDF pretreated by cellulase, xylanase, and a cellulase/xylanase mixture were 31.9% (w/w), 25.7% (w/w), and 39.7% (w/w) respectively. When comparing single enzyme pretreatment with combined enzymatic treatment, we observed differences in properties related to molecular weight and viscosity. SDF obtained by xylanase pretreatment rendered better results for glucose dialysis retardation index (32.98%, w/w), amylase inhibitory effect (56.2%), and pancreatic lipase inhibitory activity (55.33%), while combined enzymatic pretreatment exhibited better effect in properties related to exposure of functional groups and specific surface area, including sodium cholate binding capacity (72.2%) and hydroxyl radical scavenging activity (87.57%). Our results indicated that enzymatic pretreatment, which could effectively hydrolyse cellulose and hemicellulose components, could not only benefit the yield of SDF, but also enhance its physiological and functional properties.

Keywords: Enzyme-assisted extraction; Physicochemical and functional properties; Soluble dietary fibre from potato pulp.