Isomaltooligosaccharide synthesised from rice starch and its prebiotic properties in vitro

Summary The isomaltooligosaccharides (IMOs) were produced from rice starch with a maximum conversion yield of 84% and had a concentration of 372.5 mg mL−1. Compositions of IMO consisted of 26.7% isomaltohexaose (DP6), 16.2% isomaltotetraose (DP4), 19.6% d‐panose (DP3), 21.4% and isomaltose (DP2) and had a dietary fibre content of 1.1%. In vitro (consisted of three vessels) fermentation of instant Sang‐Yod rice porridge (ISYRP) mixed with IMO showed a slight increase in beneficial bacteria, bifidobacteria and lactobacilli. On the other hand, the pathogenic bacteria, clostridia and bacteroides were decreased (P < 0.05). The highest prebiotic index (PI) was found in Vessel 1 (0.13). Butyric acid was found at the highest concentration on day 11 (75.1 mm), and it was decreased at day 21 (63.4 mm) in Vessel 1. In conclusion, the ISYRP mixture of IMO was showed a good preference in prebiotic properties.