Polysaccharides-protein interaction of psyllium and whey protein with their texture and bile acid binding activity

Abstract

Dietary fiber is a group of important food polysaccharides, which may improve gastrointestinal function and alter the bioavailability and nutritional value of other food components. The interaction mechanism of psyllium fiber (PSY) and whey protein (WP) and the influence on the characteristics of polysaccharides and protein were investigated. The results of circular dichroism spectra and differential scanning calorimetry analysis showed that PSY could protect WP by increasing its melting temperature. The textural profiles implied that WP could improve the edibility of the psyllium fiber. The IR spectrum and colorimetric assay indicated the product of Maillard reaction between psyllium and whey protein with the heating condition. The SEM showed that the structure of the mixture became stronger with higher temperature. Furthermore, the mixture with the ratio of WP/PSY as 1:2 had three times of the bile acid binding ability of PSY, which could be developed as a nutraceutical additive with prevention of hyperlipidemia.