中国及び韓国の市場品「神麹」における菌叢と含有成分の実態調査

抄録

“Shinkiku” is a traditional digestive drug prepared by the fermentation of wheat and some herbs with fermentative microbes. Shinkiku is manufactured in China and Korea, and also used in Japanese Kampo medicine as a component of Hangebyakujutsutemmato. However, there are currently no quality standards for shinkiku, and thus, the quality of shinkiku has considerable variation depending on its manufacturer. Although these variations would be partially derived from the differences in fermentative microbes, there are no studies about microbial diversities or chemical constituents in commercial shinkiku. Thus, we investigated the microbial diversity and chemical constituents of 15 commercial shinkiku samples to standardize its quality. PCR-denaturing gradient gel electrophoresis of 16S rDNA and ITS1 sequences revealed that different microbes such as Lactobacillus sp. and Candida sp. were present in each shinkiku sample. On the other hand, most shinkiku samples showed amylase (12/15 samples) and lipase activities (9/15 samples) that behave as digestants. In addition, all samples commonly contained ferulic acid (>10 nmol/g), which has anti-inflammatory and anti-oxidant activities. Thus, enzyme activities and ferulic acid were suggested to be one of the candidates for use as reference standards for the quality control of shinkiku. Exceptional shinkiku samples without enzyme activities showed a baked brown color, and ferulic acid content was inversely related with the brightness color of shinkiku (R²=0.47). Therefore, it seems that color indices would be effective to predict the quality of shinkiku such as enzyme activities and ferulic acid.