Limited information is available on the changes of the isoflavone
profiles and the interconversion of soy isoflavones in soy
germ via soaking in vinegar. In this work, Yongchun Monascus aged
vinegar could increase free isoflavones (aglycone forms) so as to
enhance the nutritional values of soy germs. Effects of the solidto-
liquid ratios on the interconversions of soy isoflavone forms
were evaluated to optimize the vinegar soaking process. The soybean
germ and soaking liquor were lyophilized to yield soybean
germ powder for isoflavone analysis by developed HPLC. The isoflavone
profiles of soy germs after the vinegar soaking at the selected
solid/liquid ratios are shown in Fig. 2.