ARS | Publication request: In vitro fermentation of alternansucrase raffinose acceptor products by human gut bacteria

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2011
Publication Date: September 13, 2011
Citation: Hernandez-Hernandez, O., Cote, G.L., Kolida, S., Rastall, R.A., Sanz, M. 2011. In vitro fermentation of alternansucrase raffinose acceptor products by human gut bacteria. Journal of Agricultural and Food Chemistry. 59(20):10901-10906.

Interpretive Summary: We have developed a method that uses a food-grade bacterial enzyme to modify carbohydrates from agricultural co-products and convert them to new carbohydrates with potential applications in food and feed. Raffinose is a carbohydrate that arises from the production of soy protein, soy oil, biodiesel, sugarbeet molasses, cotton, and cottonseed oil. This new process modifies raffinose to give novel carbohydrates that show promise as prebiotics, which enhance the growth of beneficial bacteria. Thus, these agricultural co-products may serve as a source of prebiotic carbohydrates. This process could be used in the production of valuable food and feed additives.

Technical Abstract: In this work, in vitro fermentation of alternansucrase raffinose acceptor products, previously fractionated according to their degree of polymerization (DP; from DP4 to DP10) was carried out using pH-controlled small scale batch cultures at 37ºC under anaerobic conditions with human faeces. Bifidogenic activity of oligosaccharides with DP4-6 similar to that of lactulose was observed. However, lactobacillus, bacteroides, Atopobium cluster and Clostridia group did not show significant changes during incubation. Acetic acid was the main SCFA produced during fermentation process; the highest levels were shown by alternansucrase raffinose acceptor pentasaccharides at 10 h (63.11 mM) and heptasaccharides at 24 h (54.71 mM). No significant differences between the gas volume produced by the mixture of raffinose-based oligosaccharides (DP5-DP10) and the inulin after 24 hours of incubation were detected, whereas, lower gas volume was generated by DP4 oligosaccharides. These findings indicate that novel raffinose-derived oligosaccharides could be a new source of prebiotic carbohydrates.