In vitro Starch Digestibility and in vivo Glycaemic Responses of Different Varieties of Wheat in Normal Rats

The in vitro digestibility of the starch in different varieties of wheat by amylase and the glycaemic responses of rats to the starch in the wheat varieties were investigated. There were significant (p<0.05) differences in the in vitro digestibility of the starch in the different varieties of wheat with veery 601 and Induc 66 varieties recording the lowest digestibility and chre. 5386 the highest. The digestibility was inversely correlated with the proximate protein (r = -0.736), fat (r = -0.709) and crude fibre (r = -0.807) content in the wheat. `veery 601 and Induc 66 varieties elicited the lowest glycaemic responses in rats as compared to other varieties. The glycaemic responses elicited by the various variety of wheat was negatively correlated with the proximate protein and fibre contents of the varieties of wheat. The glycaemic response was also positively correlated with the in vitro digestibility of the starch content (r = 0.533). It is therefore concluded that the differences in the macromolecular composition of the varieties of wheat are significant in determining the rate of in vitro digestibility of and glycaemic responses to the starch content. This may be important in formulating wheat-based diets for special conditions such as diabetes.