In vitro fermentation of polysaccharides of rye, wheat and oat brans and inulin by human faecal bacteria

• Published in: Journal of the science of food and agriculture Vol. 80; no. 10; pp. 1469 - 1476
• Main Authors: Karppinen, Sirpa, Liukkonen, Kirsi, Aura, Anna-Marja, Forssell, Pirkko, Poutanen, Kaisa
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.08.2000; Wiley; Published for the Society of Chemical Industry by Elsevier Applied Science
• Subjects: arabinoxylan; Biological and medical sciences; Feeding. Feeding behavior; fermentation; Fundamental and applied biological sciences. Psychology; in vitro; inulin; oat bran; rye bran; Vertebrates: anatomy and physiology, studies on body, several organs or systems; wheat bran; β-glucan; Human; Cereal bran; Oat; Digestive system; Gut; Microflora; Fermentation; In vitro; Inulin; Cereal; Bacteria; Dietary fiber; Polysaccharide; Wheat; Comparative study; Rye
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/1097-0010(200008)80:10<1469::AID-JSFA675>3.0.CO;2-A

The in vitro fermentabilities of rye, wheat and oat brans and of a commercial fibre preparation, inulin, were compared. The brans were first digested enzymatically to remove starch and protein. The digested brans and inulin were then fermented with human faecal inoculum. The progress of fermentation was studied by following the consumption of carbohydrates and the production of short‐chain fatty acids and gases. Inulin, a short fructose polymer, was consumed significantly faster than the more complex carbohydrates of cereal brans. Carbohydrates of oat bran (rich in β‐glucan) were consumed at a higher rate than those of rye and wheat brans (rich in arabinoxylan). In all brans, glucose was consumed faster than the other main sugars, arabinose and xylose, and arabinose was degraded only slightly. The total production of short‐chain fatty acids was slightly higher with oat bran than with rye and wheat brans and inulin. In the fermentation of inulin, relatively more butyric acid and less propionic acid were produced than in the fermentation of brans. The decrease in pH was also greater in the case of inulin. Wheat bran led to a slightly slower gas formation than rye and oat brans. Formation of gases was fastest and greatest in the case of inulin. In conclusion, rye, wheat and oat brans were fermented in a rather similar way. Fermentation of the brans was different from that of inulin. Cereal brans might serve as a more balanced source of dietary fibre supplement than gas‐producing, readily fermentable polysaccharides such as inulin. © 2000 Society of Chemical Industry