<i>In-Vitro</i> Fermentation by Human Fecal Bacteria and Bile Salts Binding Capacity of Physical Modified Defatted Rice Bran Dietary Fiber

Abstract

Defatted rice bran dietary fiber (DRBDF) was modified by micronization, ultrasound, microwave and extrusion cooking. We investigated the impacts of these physical treatments on the fermentation ability and bile salts binding capacity of DRBDF. In-vitro fermentation by human fecal bacteria of modified fibers showed that the major fermentation products were propionic, acetate and butyrate acid. Fermentation of extruded fiber gave the highest amounts of propionic and acetic acid 135.76 and 25.45 mmol/L respectively, while, the fermented product with microwaved fiber had the highest butyric acid content (10.75 mmol/L). The amount of short-chain fatty acid increased from 12 h to 24 h and propionic acid was the predominant. On the other hand,in-vitrobile salts binding showed that extruded fiber had higher affinity with sodium deoxycholate and sodium chenodeoxycholate (66.14% and 30.25% respectively) while microwaved fiber exhibited the highest affinity with sodium taurocholate (14.38%). In the light of obtained results we can affirmed that these physical treatments significantly improved the fermentation products and bile salts binding capacity of DRBDF. Extrusion compared to the other physical treatment methods used in this study has greatly and positively influenced the fermentation and bile binding capacity of DRBDF.