Analysis and Applications of Useful Food-Derived Resources Using Novel Techniques

Abstract

This study focuses on the development of a novel extraction method using subcritical fluids, the application of innovative techniques for analyzing the bacterial community of fermented foods, and the establishment of a novel method for isolating an unknown microorganism. To achieve efficient extraction of food-derived components, a subcritical fluid extraction method employing aqueous organic solvents was devised. The results demonstrated improved extraction efficiency compared to conventional subcritical water extraction methods. Additionally, a small-scale subcritical water treatment system was developed and applied to elucidate the thermal degradation characteristics of major components in Japanese peppermint essential oil. Furthermore, a bacterial community analysis of a traditional naturally fermented vegetable beverage (kôso liquid) revealed the dominance of an unknown lactic acid bacterium (LAB). This LAB exhibited characteristics of being difficult to culture, and pure culture was initially unachievable. However, a novel isolation method devised by the author enabled successful pure cultivation. The newly isolated LAB was named Apilactobacillus kosoi. Collaborative research further demonstrated that this bacterium exhibits remarkably high intestinal immunomodulatory activity. It was clarified that a novel lipoteichoic acid component in its cell wall contributes significantly to its immunostimulatory effects.