AUTHOR=Wang Zitai , Okutsu Kayu , Futagami Taiki , Yoshizaki Yumiko , Tamaki Hisanori , Maruyama Takuro , Toume Kazufumi , Komatsu Katsuko , Hashimoto Fumio , Takamine Kazunori 

TITLE=Microbial Community Structure and Chemical Constituents in Shinkiku, a Fermented Crude Drug Used in Kampo Medicine

JOURNAL=Frontiers in Nutrition

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2020.00115

DOI=10.3389/fnut.2020.00115

ISSN=2296-861X

ABSTRACT=<p><italic>Shinkiku</italic> (Massa Medicata Fermentata) is a traditional crude drug used to treat anorexia and dyspepsia of elder patients in east Asia. <italic>Shinkiku</italic> is generally prepared by the microbial fermentation of wheat and herbs. <italic>Shinkiku</italic> is also used in Japanese Kampo medicine as a component of 半夏白朮天麻湯 (<italic>Hangebyakujutsutemmato</italic>). However, the quality of <italic>shinkiku</italic> varies by manufacture because there are no reference standards to control the quality of medicinal <italic>shinkiku</italic>. Thus, we aim to characterize the quality of various commercially available <italic>shinkiku</italic> by chemical and microbial analysis. We collected 13 <italic>shinkiku</italic> products manufactured in China and Korea and investigated the microbial structure and chemical constituents. Amplicon sequence analysis revealed that <italic>Aspergillus</italic> sp. was common microorganism in <italic>shinkiku</italic> products. Digestive enzymes (α-amylase, protease, and lipase), organic acids (ferulic acid, citric acid, lactic acid, and acetic acid), and 39 volatile compounds were commonly found in <italic>shinkiku</italic> products. Although there were some commonalities in <italic>shinkiku</italic> products, microbial and chemical characteristic considerably differed as per the manufacturer. <italic>Aspergillus</italic> sp. was predominant in Korean products, and Korean products showed higher enzyme activities than Chinese products. Meanwhile, <italic>Bacillus</italic> sp. was commonly detected in Chinese <italic>shinkiku</italic>, and ferulic acid was higher in Chinese products. Principal component analysis based on the GC-MS peak area of the volatiles also clearly distinguished <italic>shinkiku</italic> products manufactured in China from those in Korea. Chinese products contained higher amounts of benzaldehyde and anethole than Korean ones. Korean products were further separated into two groups: one with relatively higher linalool and terpinen-4-ol and another with higher hexanoic acid and 1-octen-3-ol. Thus, our study revealed the commonality and diversity of commercial <italic>shinkiku</italic> products, in which the commonalities can possibly be the reference standard for quality control of <italic>shinkiku</italic>, and the diversity suggested the importance of microbial management to stabilize the quality of <italic>shinkiku</italic>.</p>