Characterization of passion fruit seed fibres - a potential fibre source

Raw passion fruit (Passiflora edulis) seed is rich in crude lipid (24.5 g/100 g) and insoluble dietary fibre (64.1 g/100 g). After defatting, the insoluble fibre-rich fractions (FRFs), including insoluble dietary fibre, alcohol-insoluble solids and water-insoluble solids (84.9-93.3 g/100 g) became the predominant component in the (defatted) seed, and were mainly composed of cellulose, pectic substances and hemicellulose. These insoluble FRFs had water- and oil-holding capacities comparable with those of cellulose, while their bulk densities and cation-exchange capacities were significantly (P < 0.05) higher than those of cellulose. All FRFs exhibited significant (P < 0.05) effects in absorbing glucose and retarding amylase activity, and might help control postprandial serum glucose. These results underline the value of consumption of these FRFs as fibre sources or low calorie bulk ingredients in food applications. Further investigations on the in-vivo hypoglycemic effect and other physiological properties of these FRFs, using animal feeding experiments, are underway. (C) 2003 Elsevier Ltd. All rights reserved.