Fighting diabetes: Technological strategies to reduce the glycaemic index of starchy foods.
Diabetes represents one of the most serious chronic disease in the world. According to WHO data, as of 2012, 347 million people worldwide have diabetes (≈ 1 million in the Netherlands), and estimated 1.5 million deaths were directly caused by diabetes. WHO projects that diabetes will be the 7th leading cause of death in 2030. It has been thus properly defined as a “silent killer of pandemic proportions”. A growing body of evidence supports a positive correlation between glycaemic index (GI) and glycaemic load (GL) and risk of developing diabetes. The GI has been proposed as a ranking based on the blood glucose response after eating a food relative to consumption of white bread or a glucose solution.
Aim In this project we will explore strategies on how to reduce the GI of starchy foods like pasta, bread, potatoes and rice.
Approach Several approaches can be used to reduce the GI of starchy foods:
1) incorporation or co-ingestion of natural compounds that are known for inhibiting α-amylase activity (like polyphenols);
2) incorporation or co-ingestion of soluble dietary fibre that increases the viscosity of digesta or that physically encapsulate the starch granules in foods;
3) structuring the food matrix in such a way to reduce the starch granules gelatinisation during cooking or their accessibility to α-amylase during digestion;
4) screening and selecting new varieties of starchy raw materials (cereals, potatoes, rice, etc.).A static in vitro model of digestion which simulates the gastric and the duodenal digestive phase will be used.
All the strategies mentioned above need to be tested in a realistic food model in order to assess the effect of food matrix, processing (e.g. thermal treatment) and digestion (stability towards changes in pH). The GI of food will be predicted by measuring the kinetics and the extent of starch hydrolysis (i.e. the amount of glucose released over time). Different analytical techniques will be used depending on the strategy adopted: Microscopic and imaging techniques to characterize the macrostructure and microstructure of the tested foods, rheological measurement of digesta (viscosity, viscoelastic properties), etc.