Mastication or masceration: does the preparation of sample affect the predictive in vitro glycaemic response of pasta?

A series of experiments were conducted to evaluate the effect of different sample preparation steps, prior to the in vitro starch digestion process, on the predictive in vitro glycemic response of durum wheat pasta (control), and pasta made with durum wheat semolina and pea flour combinations. The physico-chemical, textural, and cooking quality of the pastas were also assessed. The evaluation of the different preparations processes illustrated that the maceration of the samples prior to starch digestion significantly increased the extent of starch degradation and hence the area under the curve (AUC) of reducing sugar released during the digestion process. Mastication of the samples prior to in vitro assessment increased the initial reducing sugar content of samples but yielded the lowest recorded AUC for all samples. The replacement of durum wheat semolina with pea flour significantly reduced the samples AUC compared to the control samples when prepared by mastication. This difference was not apparent for the samples prepared by maceration. The results indicate that the choice of the preparation step used prior to in vitro starch digestion procedures can significantly affect the predictive glycemic response – AUC values of samples, and hence manipulate differences attributed to product composition or structure. This may have an impact in terms of choosing the most appropriate method of glycemic analysis for the food industry.