Preparation of a probiotic rice tablet: Sensory evaluation and antioxidant activity during gastrointestinal digestion

Abstract

Broken rice produced during rice processing had a poor taste, thus was not accepted by consumers. Milling and fermentation could make broken rice applicable material for food use. In this study, indica rice flour was used as raw material to prepare fermented rice tablets with probiotic effects. A starter composed of Brettanomyces custersii ZSM-001 and Lactobacillus plantarum ZSM-002 were used, and the sensory properties of the resulting tablet was similar to the tablet prepared with commercial starters. Compounds affecting sensory properties, e.g. sugars, organic acids, and volatiles were analyzed, with an obvious change in volatiles after fermentation. The cell density change of Lactobacillus plantarum ZSM-002 during in vitro gastrointestinal (GI) digestion was studied, which was still higher than the minimum for probiotics to exert probiotic effect. The antioxidant activities of rice tablets during GI digestion were analyzed, with the tablet fermented with Brettanomyces custersii ZSM-001 and Lactobacillus plantarum ZSM-002 showing the highest activity. This study reported the feasibility of preparing a probiotic rice tablet with good sensory properties using indica rice flour, which may enrich fermented rice products and increase the usage of broken rice in the food industry.