Polyphenols from Persimmon Fruits as a Functional Foods Material

Abstract

Persimmon is well known to be a polyphenol-rich fruit. The polyphenol fraction (PPfr) was obtained from persimmon fruits using a novel method, and its effect on postprandial blood glucose levels in rats and humans was examined. PPfr contained 20% carbohydrate and 70% polyphenol which consisted of epicatechin : epicatechin gallate : epigallocatechin : epigallocatechin gallate at a ratio of 1 : 1 : 3 : 2. In vitro studies revealed that lowering effect of PPfr on blood glucose after carbohydrate ingestion was attributable to the inhibition of digestive enzymes, such as alpha-amylase and maltase, as well as the inhibition of glucose absorption through the digestive tract. Following the administration of 3 g PPfr to 10 healthy human volunteers with 150 kcal maltose, postprandial blood glucose was significantly lowered compared with placebo. These results suggest that PPfr from persimmon fruits was useful for blood glucose control and the primary prevention of diabetes.