glucose release during in vitro digestion of wheat

The research investigated the dynamics of released glucose from whole wheat flour during in vitro gastric and intestinal digestion. Two experiments were conducted. Experiment 1 (gastric digestion) was an enzymatic hydrolysis with a pepsin solution at pH 2.0 and 37°C for 120 minutes. In experiment 2, first step was followed by the hydrolysis with the multi-enzyme pancreatin (intestinal digestion), at pH 6.8 and 37°C for 4 h. The released glucose (RG) and the refractive index (RI) were determined from the supernatant obtained after centrifugation. Experiments showed an initial increase in the glucose released from 1 g wheat up to 0.472 mg/mL after 1 h of gastric digestion, then followed by decrease. The lowest value was recorded after 2 hours of gastric digestion (0.332 mg/mL). The concentration of the reducing sugars increased throughout the intestinal digestion from 0.549 mg/mL up to 1.990 mg/mL, as a result of starch hydrolysis to dextrins, maltose and then to glucose. The high positive correlation between RG and RI suggests that RI may be used as a simple and rapid method for estimating the released glucose during in vitro digestion.