Changes in physicochemical components of Astragalus membranaceus fermented with Phellinus linteus

Abstract

This study analyzed the changes in physicochemical components of Astragalus membranaceus (AM) fermented with Phellinus linteus. Moisture content, pH, total acidity, total reducing sugar content, extraction yield, free sugar content, free amino acid and isoflavonoid (calycosin, formononetin) were investigated. The moisture content was increased during fermentation with Phellinus linteus. The pH level increased while the total acidity significantly decreased during fermentation. The reducing sugar content were in the range of 0.32~0.61%. The extraction yield using water was higher than that using 80% ethanol. The major free sugars were identified as glucose, fructose, sucrose and the content of free sugars decreased through fermentation. However, the glucose and sucrose contents of the water extracts were increased. In addition, the free amino acid increased significantly during fermentation. Finally, calycosin and formononetins contents in water extracts of after 30 days of AM fermentaion with Phellinus linteus were (3.91 mg/100 g) and (1.38 mg/100 g), respectively. These results suggest that fermentation with Phellinus linteus could be used to increase the bioactivity of AM. The mycelium-fermented AM could be a valuable source of functional material and edible resource for industry.