Postprandial Glucose and Insulin Responses to Processed Rice Products in Normal Subjects

Abstract

The influence of physical forms of gelatinized rice products on enzymatic hydrolysis in vitro and glycemic and insulinemic responses in normal subjects were studied. Densities of garaeduk, bagsulgi, and cooked rice were 1.20, 1.18 and 1.11 g/mL, respectively, while moisture contents of garaeduk, bagsulgi, and cooked rice were 47.5, 43.1 and 66.0% (wt.), respectively. The highest initial rate of in vitro hydrolysis by porcine pancreatic α - amylase was observed in bagsulgi followed by cooked rice and garaeduk. However, time for complete hydrolysis seemed to reach a plateau value. Postprandial glucose and insulin responses and satiety of rice products were studied in 12 normal subjects (mean age 23.2±2.4 years, 6 men and 6 women). Postprandial serum glucose and insulin levels, after consumption of the rice products, reached a peak at 30 min. Garaeduk showed significantly less incremental responses for glucose (1627.5±134.9 mgㆍmin/dL) and insulin (2041±287.0 μUㆍmin/mL) than did bagsulgi for glucose (2407.4±208.3 mgㆍmin/dL) and insulin (3582±264.4 μUㆍmin/mL). Satiety responses to the rice products were not significantly different. Therefore, it can be concluded that garaeduk may be more beneficial in controlling postprandial hyperglycemia and hyperinsulinemia than bagsulgi. These results also suggest that physical properties of starch products, acquired by the specific processing methods, affect postprandial metabolism of carbohydrate foods.