Objectives　We developed a fermented tea by mixing loquat leaves and third crop green tea leaves at the level of 1：9. We investigated whether the fermented tea affects postprandial blood glucose levels in healthy volunteers.
Methods　Test was performed by a single-blind titration method. Low and high concentration fermented tea beverages were prepared by extracting 2 g and 3 g fermented tea leaves, respectively, with 200 mL hot water. Fifty subjects consumed placebo beverage, low concentration fermented tea beverage and high concentration fermented tea beverage, followed by a carbohydrate loading diet, and the levels of blood glucose were measured after 30, 60, and 120 min.
Results　Feeding the high concentration fermented tea beverage showed the tendency to suppress the elevation of postprandial blood glucose levels. The suppression was significant at 30 min in subjects who exhibited higher increment of blood glucose levels after meals, compared to feeding the placebo beverage.
Conclusions　These results suggested that the fermented tea made from loquat leaves and green tea leaves has suppressive effect on the elevation of postprandial blood glucose levels.