Human intervention studies indicate a broad range of health benefits emanating from dietary fibres such as the prevention of constipation, the regulation of cholesterol, the reduction of the risk of diabetes and colon cancer and the support of the growth of beneficial microorganisms. Variable effects have been reported for post-prandial glucose levels after ingestion of soluble and insoluble dietary fibres. Thereby, soluble dietary fibres are associated with lower post-prandial glucose levels.
The viscosity of the soluble dietary fibres, which is affected by concentration and molecular weight, seems to play an important role for this effect. For insoluble dietary fibres, the mechanisms are still unclear. However, other effects of fibre lengths, water binding, water retention or reduction in starch digestion as well as the effects of food processing like pH shift, heating, homogenization or freezing-thawing, on glucose release still remain unclear.
Therefore, the present project will focus on the determination of effects of dietary fibres on in-vitro glucose release in the small intestine.
Thereby pure fibre ingredients as well as model foods and food prototypes developed by the industrial partners will be chosen and their effect on glucose release will be monitored in a diffusion-based in-vitro model simulating human oral, gastric and small intestine digestion. The findings obtained will be evaluated in short-term human intervention studies (Module 2) to establish and validate influencing factors on glucose metabolism as well as improve the in-vitro digestion model for predicting effects of dietary fibre addition to food on glucose metabolism.