Fermented barley bran addition improved the digestive properties, gastrointestinal phenol release and the antioxidant activities of extruded rice

Abstract

Fermented barley can be used as functional staple food ingredient. In the present study, the effect of fermented barley bran addition on extruded rice was investigated in terms of digestive properties, gastrointestinal phenol release and antioxidant activities. Different nutrient compositions were observed between fermented barley fortified rice (FBFR) and barley fortified rice (BFR). After fermented barley bran addition, the resistant starch proportion increased to 17.49% and the glycemic index decreased to 68.82 in FBFR. The release of phenols was more significant in FBFR than BFR during digestion and colonic fermentation, leading to better in vitro antioxidant activities. Among phenolic compounds, ferulic acid exhibited different variation tendencies between BFR and FBFR during colonic fermentation. According to the results of microbiota analysis, higher Lactobacillus and Bifidobacterium abundance were observed in FBFR fermented faecal samples. Correlation network analysis further revealed the potential role of Megasphaera and Bifidobacterium on the biotransformation specific phenols.