Modification of Ginseng Insoluble Dietary Fiber by Enzymatic Method: Structural, Rheological, Thermal and Functional Properties

Abstract

In this study, the effects of enzymatic modification using cellulase/xylanase on the composition and structural and functional properties of ginseng insoluble dietary fiber (G-IDF) were evaluated. Fourier transform infrared spectroscopy and scanning electron microcopy showed that enzymatic extraction treatment caused obvious structural alterations in ginseng-modified (G-MIDF) samples, which exhibited more porous and completely wrinkled surfaces. Comparing the peak morphology of G-MIDF with untreated IDF using X-ray diffractometry, the G-MIDF sample exhibited split peaks at a 2θ angle of 23.71°, along with the emergence of sharp peaks at 28.02°, 31.78°, and 35.07°. Thermo-gravimetric analysis showed that G-MIDF exhibited a specified range of pyrolysis temperature and is suitable for food applications involving processing at temperatures below 300 °C. Overall, it was evident from rheograms that both G-IDF and G-MIDF exhibited a resemblance with respect to viscosity changes as a function of the shear rate. Enzymatic treatment led to significant (p < 0.05) improvement in water holding, oil retention, water swelling, nitrite ion binding, bile acid binding, cholesterol absorption, and glucose absorption capacities.

Keywords

• insoluble dietary fiber
• ginseng residue
• enzymatic treatment
• physicochemical properties
• functional characteristics
• hydration properties