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Ripening temperature affects the content and distribution of isoflavones in sufu, a fermented soybean curd
Author(s) -
Huang YungHsin,
Lu TingJang,
Chou ChengChun
Publication year - 2011
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.2010.02479.x
Subject(s) - ripening , aglycone , chemistry , food science , fermentation , isoflavones , aspergillus oryzae , biochemistry , glycoside , organic chemistry
Summary 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 °C for a period of 16 days. It showed that the 16‐day ripened sufu contains less total isoflavone content (629.29–739.68 μg g −1 dried matter) than the salted tofu before ripening (942.59 μg g −1 dried matter). Regardless of ripening temperature, ripening causes a major reduction in the content of β‐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 °C 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 °C. Meanwhile, the distribution of aglycone increased from 13.17% to 39.88%.