Isomaltooligosaccharide synthesised from rice starch and its prebiotic properties in vitro

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.     

Starch‐based carbohydrates display the bifidogenic and butyrogenic properties in pH‐controlled faecal fermentation

Starch‐based carbohydrates, native rice starch (NRS), isomaltooligosaccharide produced from native rice starch (rIMO), commercial isomaltooligosaccharide (cIMO), resistant starch type 2 (RS2) and type 3 (RS3) were investigated the bifidogenic and butyrogenic properties. The result confirmed that the bifidogenic effect of rIMO (9.8 ± 0.18) was comparable to cIMO (10.3 ± 0.2). In addition, rIMO showed the highest support on growth of bifidobacteria during early fermentation (10 h), and it was not significantly different (P > 0.05) from cIMO after up to 70 h. Prebiotic index (PI) at 24 h fermentation of rIMO and cIMO was shown positive value and higher than RS3 and RS2. Meanwhile, NRS showed negative value means it has no prebiotic property. Interestingly, RS3 showed approximately twofold in butyrate production (132.3 mm ) compared to rIMO and cIMO. In conclusion, IMO showed high bifidogenic effect; meanwhile, RS3 showed high butyrogenic property.