Effect of Replacing Sucrose by Isomaltulose in Green Tea Beverage on Postprandial Glucose Level and Antioxidant Capacity in Healthy Subjects

Abstract

Green tea provides many health benefits such as decreasing postprandial glucose levels, lowering blood cholesterol, and preventing cardiovascular disease. However, the addition of sweeteners such as sucrose in the beverage may reduce antioxidant capacity and diminish health benefits of green tea. Therefore, the aim of this study was to examine the effects of replacing sucrose by isomaltulose, the alternative sweetener, in green tea beverage on postprandial glucose and antioxidant capacity in healthy subjects. Eighteen healthy subjects (male and female aged 18-35 years) were randomized into five groups to drink 400 mL of each beverage containing; 1) 50 g sucrose (SU), 2) 50 g isomaltulose (ISO), 3) green tea (GT), 4) green tea with 50 g sucrose (GTS), or 5) green tea with 50 g isomaltulose (GTI) with crossover-design. Total polyphenols content in GT, GTI, GTS (400 mL) were 481±7.76 mg gallic acid equivalent with no significant difference in ferric ion reducing antioxidant power (FRAP). After 12-h fasting, postprandial plasma glucose and FRAP of subjects were determined at each time point from 0 to 120 min after beverage consumption. We found that the incremental area under the curves of plasma glucose (iAUC-G) of ISO, GT, GTS and GTI were significantly lower than that of SU. Interestingly, iAUC-G of GTS was not different from ISO, whereas iAUC-G of GTI was significantly lower than that of ISO. Furthermore, GTS showed a significantly decrease in the iAUC of plasma FRAP level (iAUC-F), when compared with GT. Nevertheless, iAUC-F of GTI was significantly higher than GTS, but not significantly lower than GT. In conclusion, this study demonstrated that the substituting sucrose with isomaltulose in green tea beverage can help regulate postprandial plasma glucose level and improve antioxidant capacity.