Hypoglycemic Effect of Dry Heat Treated Starch With Xanthan: An In Vitro and In Vivo Comparative Study

Abstract

The hypoglycemic effects of dry heated starches are evaluated based on the correlation between their in vitro starch digestibility and in vivo glucose responses. High amylose rice starch is modified by dry heat treatment with xanthan at 130 °C for 2 h, and all starch samples are gelatinized for further analysis. Dry heat treatment reduces rapidly digestible starch content by 10.2–38.9% and increases resistant starch content by 9.3–28.1% in the results of in vitro starch digestibility. Regarding in vivo glucose responses, dry heat-treated starches also lower the postprandial increase in blood glucose level than native starch, and dry heat treated starch with xanthan has the lowest glycemic index (GI, 71.4), showing the similar tendency of in vitro results. The linear regression equation obtained from the correlation analysis with the in vitro and in vivo data was GI = 1.69 (hydrolysis index) − 18.30. This new equation based on a gelatinized modified starch sample can be used as a predictor of GI in mice from in vitro data to develop new functional materials. Dry heat treatment with xanthan is an effective method to lower GI in gelatinized form in vivo as well as in vitro.