Prebiotic potential of enzyme-converted durum wheat
Researchers from the Universities in Naples, Reading and Barcelona report that treating the insoluble cereal fibre with Trichoderma enzymes produced soluble feruloyl oligosaccharides, which displayed bifidobacteria and lactobacilli-boosting properties when tested in a model gut system.
If human studies confirm the prebiotic potential of the new fibres, it could see the soluble feruloyl oligosaccharides from durum wheat joining the growing market of prebiotic ingredients, currently ruled by inulin and fructooligosaccharide.
The research also taps into the growing trend for developing new fibres with potential prebiotic activity. Prof Glenn Gibson, co-author of the study, told NutraIngredients.com that there will “definitely” be more and more research into new and novel potential prebiotics. “We have plans and so do others,” he said.
“There is quite a bit on using enzymes to derive potential prebiotics from other carbohydrates and something we are very interested in, especially if you can derive bioactive ingredients from something that would otherwise be waste, and then there are obvious commercial advantages, too,” said Prof Gibson.
Prof Gibson added that no human trial is currently planned, “but it would be good to do so”. He added that an earlier double-blind, placebo-controlled, crossover study, funded by CPUK, showed that daily whole grain wheat consumption did exert a “pronounced prebiotic effect on the human gut microbiota composition”, according to results published in the British Journal of Nutrition (Jan. 2008, Vol. 99, Pages 110-120).
Study details
According to the report in the journal Nutrition, Metabolism & Cardiovascular Diseases, the researchers treated durum wheat fibre (DWF) with Trichoderma Harzianum strain 22. This produced soluble feruloyl oligosaccharides.
These soluble fibres were subsequently tested in a model gut system, which mimics the microbial environment of the human colon.
Results showed that the enzyme-treated durum wheat fibre (ET-DWF) did stimulate the growth of bifidobacteria and lactobacilli. No effect on short-chain fatty acids formation was recorded by the researchers.
“This study demonstrated that pre-treatment of DWF with tailored Trichoderma enzymes provided, in contrast to the native DWF, in contrast to the native DWF, a material with bifidogenic activity in vitro which was comparable to that of common and well known soluble DF,” wrote the researchers.
“However, in order to classify ET-DWF as a prebiotic in vivo studies are necessary to prove that this fibre withstands digestion in the upper gastrointestinal tract which is a requirement for a prebiotic polysaccharides.”
The new study was performed with ‘in house’ funding from the University of Reading and their collaborators.
Power of the enzyme
German scientists recently reported that by playing with the starting sugars and applying enzymes, potentially novel prebiotic fibres could be produced.
According to their findings in the Journal of Biotechnology, use of an A5 variant of levansucrase, which reportedly favours the production of short chain oligosaccharides and not long polymers, and the Xyl-Fru substrate, the researchers report that one main product was produced: a 6-kestose analogue (alpha-Xyl-(1,2)-beta-Fru-(2,6)-beta-Fru).
“As 6-kestose and XOFs have strong prebiotic activity, the impact of this novel product on the probiotic properties should be tested in mammalian gut system,” wrote the researchers from Helmholtz Centre for Infection Research and X-Zyme GmbH in Dusseldorf.
Adding to a burgeoning market?
The burgeoning prebiotic market has been largely created by three inulin producers, all based in Europe. Other ingredient manufacturers are increasingly looking to promote the prebiotic effect of their products as evidence suggests that prebiotics could be even more useful than the probiotic bacteria that they feed.
Prebiotic ingredients, or those that boost the growth of beneficial probiotic bacteria in the gut, are worth about €90 million in the European marketplace but are forecast to reach €179.7 million by 2010, according to Frost & Sullivan.
The big inulin producers, particularly Beneo-Orafti, have been influential in building the science behind inulin and oligofructose, backing research into potential benefits for a variety of health conditions ranging from bones to colorectal cancer, from immunity to satiety and weight management.
Source: Nutrition, Metabolism & Cardiovascular DiseasesPublished online ahead of print, doi: 10.1016/j.numecd.2008.07.005"Potential prebiotic activity of oligosaccharides obtained by enzymatic conversion of durum wheat insoluble dietary fibre into soluble dietary fibre"Authors: A. Napolitano, A. Costabile, S. Martin-Pelaez, P. Vitaglione, A. Klinder, G.R. Gibson, V. Fogliano
