Structure–prebiotic properties relationship for α-D-glucan from Leuconostoc citreum SK24.002

•Molecular structure of α-D-glucan subjected to nonchemical modification was assessed.•The apparent viscosity, molecular weight and percentage of α-1,6 linkages of α-D-glucan decreased after modification.•The concentration of propionic acid or butyric acid for enzymatic treated α-D-glucan was higher than that of α-D-glucan.•Enzymatic treated α-D-glucan would be a good candidate dietary fiber.

Effects of non-chemical modification on structure and fermentability of α-D-glucan from Leuconostoc citreum SK24.002 were investigated. It was found that the apparent viscosity, molecular weight and percentage of α-1,6 linkage of α-D-glucan decreased after endodextranase or ultrasonic treatment. During in vitro fermentation, a strong increase in bacterial population was observed and the largest changes took place during the first 12 h of incubation. A decreased pH was also observed and gas production after 48 h fermentation increased at the following sequence: enzymatic treated α-D-glucan < ultrasonic treated α-D-glucan < α-D-glucan. The fermentation of modified sample resulted in a consistent generation of SCFA, particularly in the 12–48 h part of incubation. The concentrations of propionic acid and butyric acid at 48 h of fermentation were 60.4 and 19.1 mM for enzymatic treated α-D-glucan, respectively, higher than ultrasonic treated α-D-glucan or α-D-glucan. This showed that enzymatic hydrolysis could be a promising degradation method for the production of potential prebiotics.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide