LAUSR

Abstract The increasing demand for functional foods has boosted up the food industry to produce fiber-enriched products. The purpose of this study was to investigate the effects of soluble dietary fiber from defatted rice bran (DRB) obtained through Trichoderma viride fermentation (F-SDF) on the physical properties and starch digestion characteristics of biscuits. Rheological analysis results showed that the addition of F-SDF delayed the gelatinization of starch. Texture profile analysis (TPA) results demonstrated that the addition of F-SDF reduced the hardness, springiness, cohesiveness, gumminess, chewiness and resilience of the biscuits. The scanning electron microscopy (SEM) results showed that F-SDF hindered the formation of the gluten network structure in the biscuits, making the biscuits loose. Meanwhile, X-ray diffraction (XRD) revealed the addition of F-SDF reduced the area of the crystallization zone. In addition, F-SDF led to a significant reduction of predicted glycemic index (pGI) of reformulated biscuits. Sensory evaluation results indicated that the effects of F-SDF addition on the odor, color and taste of the biscuits were relatively small, while the biscuits with highest texture and acceptability score were obtained by incorporating 6% of F-SDF in the formulation. In summary, adding the proper amount of F-SDF could improve the physical properties of the biscuits and exhibit potential to decrease the postprandial blood glucose level resulted by biscuits.