67B-4 |
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B.-K. KWON, J.-M. Park, Y.-I. Chang, and M. Han. R&D Center, Haechandle Foods Co. Ltd., 799 Jukbon-ri, Yeonmu-eup, Nonsan, Chungnam, 320-833, South Korea Doenjang, Korean traditional fermented soybean paste, is one of the typical fermented foods using soybean as a primary ingredient. Soy isoflavones such as daidzein, genistein, glycitein and their glycosides play beneficial roles in the prevention of chronic diseases such as hormone dependent cancers, cardiovascular diseases, osteoporosis and also reduce incidence of menopausal symptoms. It has been reported that aglycon-type isoflavone is more effective than glycoside-type isoflavone in functionality of soybean. There are many reports for extraction of isoflavone from soybean and its products. However there are no reports for extraction of isoflavone from deonjang as a fermentation food. Objectives of the studies were to optimize maximum extraction of free isoflavones in the form of aglycons during fermentation of deonjang as a mass production product in industrial scale, using response surface methodology (RSM) and to analyze isoflavones using HPLC. RSM was employed to examine and optimize the total free isoflavones extract with 3 levels of 3 factors which were the concentration of methanol (X1, 60~100%), addition of 1N HCl (X2, 0~40%,v/v) and stirring time (X3, 0~20min) at 25 degree C from doenjang. The regression equation of total free isoflavone extract in the form of aglycon was Y=53.198 + 7.724X1 - 0.630X2 + 3.547X3 - 0.010X12 + 0.064X1X2 + 0.055X22 - 0.006X1X3 - 0.125X2X3 - 0.040X32 and coefficient of determination (R2) was 0.95 (p<0.05) in this model. From this study, the opimum conditions of the free isoflavone extraction were 80.4% at methanol concentration, 3.6%(v/v) addition of 1N HCl and 15.7min of stirring time. Under these conditions, 159.7 ppm of total free isoflavone in the form of aglycon was obtained from doenjang and it was very close to 170.2 ppm of the predicted value of the model equation. These results were used as a useful tool for monitoring optimal processing condition and quality control of deonjang with measuring free isoflavones in industry.
Session 67B, Food Chemistry: Antioxidants and bioactive agents
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