Ripening temperature affects the content and distribution of isoflavones in sufu, a fermented soybean curd
Journal
International Journal of Food Science and Technology
Journal Volume
46
Journal Issue
2
Pages
257-262
Date Issued
2011
Author(s)
Abstract
Sufu, a fermented soybean curd, was prepared by ripening the salted tofu cubes in the Aspergillus oryzae-fermented rice-soybean koji mash at 25, 35 or 45 ¢XC for a period of 16 days. It showed that the 16-day ripened sufu contains less total isoflavone content (629.29-739.68 £gg g -1 dried matter) than the salted tofu before ripening (942.59 £gg g -1 dried matter). Regardless of ripening temperature, ripening causes a major reduction in the content of £]-glucoside and malonylglucoside isoflavones along with a significant increase of aglycone isoflavone content. These changes were enhanced as the ripening period extended. Among the various treatments examined, sufu ripened at 45 ¢XC showed the greatest increase in aglycone content coupled with the greatest decrease in malonylglucosides. The distribution of malonylglucosides decreased from an initial 40.32% in the tofu cube to 9.78% after 16 days of ripening at 45 ¢XC. Meanwhile, the distribution of aglycone increased from 13.17% to 39.88%. ? 2011 The Authors. International Journal of Food Science and Technology ? 2011 Institute of Food Science and Technology.
Subjects
Enzyme-ripened sufu
Isoflavone
Rice-soybean koji
Ripening temperature
Type
journal article