SCFA Profile of Rice RS Fermentation by Colonic Microbiota, Clostridium butyricum BCC B2571, and Eubacterium rectale DSM 17629

Resistant starch type 3 (RS3) produced from high amylose food sources through retrogradation or enzymatic process is known to have physiological function as dietary fiber. Fermentation of RS3 by colonic microorganisms produced SCFA (acetate, propionate, and butyrate), maintained the health of colon, balance of gut microbiota, preventing inflammatory bowel diseases (IBD) and colon cancer. RS3 in this study was produced from IR-42 and Inpari-16 broken rice by enzymatic treatment (combination of amylase-pullulanase). The Resistant Starch was fermented for 12 and 24 h by colonic microbiota (extracted from healthy human subject), Clostiridium butyricum BCC-B2571, or Eubacterium rectale DSM 17629. SCFA produced was analyzed by gas chromatography. Treatment by amylase-pullulanase combination was advantageous to increase their RS3 content. The result showed that after enzymatic process, the RS3 content of IR-42 (41.13%) was not significantly different (p < 0.05) from that of Inpari-16 (37.70%). High concentration of acetate (82.5 mM) and propionate (7.5 mM) were produced by colonic microbiota after 12 h fermentation and best concentration of butyrate (6.8 mM) was produced by colonic microbiota after 24 h fermentation. It is clear that utilization of colonic microbiota rather than single strain was better in the production of SCFA.