Transformation of Major Ginsenosides into Minor Ginsenosides in Ginseng by Pickling in Salted Rice Malt Paste

Abstract

Increasing the content of minor ginsenosides in ginseng enhances its pharmaceutical activities. For this study, minor ginsenosides F2 and CK were produced in ginseng by pickling in a salted rice malt paste fermented using Aspergillus kawachii. The A. kawachii excluded β-glucosidase in the culture broth with 125 mU/mL after 16 d cultivation, and hydrolyzed major ginsenoside Rb1 to generate F2 and CK on the pathway Rb1→Rd→F2→CK. Steamed rice was fermented by A. kawachii with 14% NaCl to produce a salted rice malt paste as a pickle bed with 165 mU/mL of β-glucosidase. Fresh 1-year-old and 6-year-old ginseng, which had Rb1 and Rd but which had neither F2 nor CK, were pickled in the salted rice malt paste for 28d. The extract showed production of F2 and CK, and changed the ratio of Rb1, Rd2, F2, and CK in ginseng.