Effect of amylose content of rice varieties on glycemic metabolism and biological responses in rats

The composition of rice grains can affect metabolic responses to rice consumption, mainly by the amylose:amylopectin ratio. Male Wistar rats were fed diets with grains of cooked rice of the cultivars BR-IRGA 409, Formosa and Mochi with high (TAH), intermediate (TAI) and low (TAL) amylose contents, respectively. During the experimental period, feed intake, body weight gain, apparent starch digestibility (ASD), wet and dry faecal production, faecal water content, faecal pH, faecal nitrogen excretion and postprandial blood glucose response were determined. Blood triglycerides and total cholesterol concentrations and liver weight were also determined. The animals in the TAH group presented lower ASD, higher wet and dry faecal production and faecal nitrogen excretion, reduced faecal pH, lower postprandial blood glucose response, serum triglyceride levels and liver weights, and higher serum total cholesterol levels. Amylose:amylopectin ratio significantly affects the rate and extension of rice starch digestion in the gastrointestinal tract, affecting some biologically relevant parameters.