Glucose Release During in Vitro Digestion of Barley

Abstract

The dynamics of released glucose (RG) and refractive index (RI) in the supernatant obtained during in vitro gastric and intestinal digestion of whole barley flour was studied. The in vitro digestion consisted of a two-step enzymatic procedure: (1) initial simulation of gastric digestion using pepsin and (2) simulation of small intestine digestion using multi-enzyme pancreatin. Experiments on 1 g barley flour showed an initial increase in RG concentration up to 0.379 mg / mL at one hour from the onset of gastric digestion, then a decrease in concentration, reaching the lowest value in 2 hours of gastric digestion (0.126 mg/mL). The concentration in reducing sugars increased throughout the intestinal digestion from 0.422 mg/mL up to 2.824 mg/mL, as a result of starch hydrolysis to dextrins, maltose and then to glucose. RI can give information on the amount of glucose released during digestion due to the high positive correlation found between RG and RI (r = 0.761).

Keywords

• barley
• released glucose
• refractive index
• digestion