Abstract
For the development of effective utilization techniques for sugi (Cryptomeria Japonica) resources, as a novel reaction medium, superheated steam was used to extract organic substances from sugi leaves in a pressure range below saturated vapor pressure at 100~200°C. The yield with superheated steam at 170°C was about five times as high as that obtained at 100°C, and the yield also increased as extraction time and steam pressure increased. Steam with higher temperature and higher pressure contributed to enhancing the oil yield and extracting more high-molecular-weight compounds such as sesquiterpenes and diterpenes. In addition, to examine the effectiveness of the extracts obtained by superheated steam, their antimicrobial activities against 18 soil microorganisms were examined using the disk-diffusion method. Extracts obtained by superheated steam exhibited significant antimicrobial activity, especially against fungi and actinomycetes. The analysis of the chemical compositions of the extracts by GC-MS and GC-FID suggested that one or more of the monoterpenes and sesquiterpenes were the substances that were potentially responsible for such antimicrobial activity. Superheated steam exhibited some advantages in selectively extracting active antifungal ingredients from natural materials.
