• Heinonen, S.-M.
• Forssell, Pirkko
• Adlercreutz, H.
• Poutanen, Kaisa
• Karppinen, Sirpa
• Aura, Anna-Marja

Abstract

Rye bran is rich both in fermentable dietary fibre and plant lignans.The fermentable dietary fibre components are arabinoxylan, beta-glucan andfructan [1], which produce short chain fatty acids and gases in bacterialfermentation in the human large intestine. Plant lignans (matairesinol,secoisolariciresinol, syringaresinol, pinoresinol and lariciresinol) areconverted to mammalian lignans by bacterial fermentation, producing enterodioland/or enterolactone [2]. The aim of the work presented here was to study theeffect of processing of rye bran on the fermentation rate of carbohydratesand formation of enterodiol and enterolactone in vitro.Processed rye bran samples were prepared. Rye bran was extruded and treatedwith xylanase. Part of the xylanase treated rye bran was separated intowater-extractable fraction and insoluble residue. All the samples weredigested enzymatically prior to the fermentation with human faecal flora invitro.Xylanase treatment of rye bran enhanced both fermentation rate ofcarbohydrates and formation of enterodiol. Water-extractable rye branconcentrate had the fastest fermentation rate and produced the highest amountof enterodiol, whereas the insoluble residue was the slowest producer ofenterodiol. Slowly occurring enterolactone formation was not affected by theform of carbohydrate.<br/>References1 . Karppinen, S., Kiiliäinen, K., Liukkonen, K., Forssell, P. and Poutanen,K. 2001. Extraction and in vitro fermentation of rye bran fractions. J. CerealSci. 34: 269-278.2. Heinonen, S., Nurmi, T., Liukkonen, K., Poutanen, K., Wähälä, K., Deyama,T., Nishibe, S. and Adlercreutz, H., 2001. In vitro metabolism of plantlignans: new precursors of mammalian lignans enterolactone and enterodiol. J.Agric. Food Chem. 49: 3178-3186.

Topics

• impedance spectroscopy
• extraction
• fermentation