Evaluation of gastric processing and duodenal digestion of starch in six cereal meals on the associated glycaemic response using an adult fasted dynamic gastric model

Abstract

Purpose: To identify the key parameters involved in cereal starch digestion and associated glycaemic response by the utilisation of a dynamic gastro-duodenal digestion model. Methods: Potential plasma glucose loading curves for each meal were calculated and fitted to an exponential function. The area under the curve (AUC) from 0 to 120 min and total digestible starch was used to calculate an in vitro glycaemic index (GI) value normalised against white bread. Microscopy was additionally used to examine cereal samples collected in vitro at different stages of gastric and duodenal digestion. Results: Where in vivo GI data were available (4 out of 6 cereal meals) no significant difference was observed between these values and the corresponding calculated in vitro GI value. Conclusion: It is possible to simulate an in vivo glycaemic response for cereals when the gastric emptying rate (duodenal loading) and kinetics of digestible starch hydrolysis in the duodenum are known.