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Effects of fermentation on antioxidant properties and phytochemical composition of soy germ
Author(s) -
Sheih IChuan,
Fang Tony J,
Wu TungKung,
Chen RuYin
Publication year - 2014
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.6666
Subject(s) - food science , fermentation , antioxidant , chemistry , trolox , phytochemical , trolox equivalent antioxidant capacity , germ , solid state fermentation , biochemistry , biology , polyphenol , antioxidant capacity , microbiology and biotechnology
BACKGROUND Traditional soy‐fermented foods, such as miso, douche, natto, and tempeh have been widely used as a dietary supplement in Asian countries, and numerous reports on their phenolics and antioxidant activities have been published. Soy germ contains 10‐fold higher phenolics than whole soybean, hence using soy germ as fermentation substrate will be more efficient than whole soybean. RESULTS Soy germ fermented with Aspergillus niger M46 resulted in a high‐efficiency bio‐transformation of phenolics and flavonoids to their metabolites, and a diverse secondary metabolic product was also found to response oxidation stress of fungal colonisation. Its antioxidant activity against hydroxyl radicals and superoxide radicals ( IC 50 = 0.8 and 6.15 µg mL −1 , respectively) was about 205‐fold and 47‐fold higher than those of unfermented soy germ ( IC 50 = 164.0 and 290.48 µg mL −1 ), respectively. These results were similar to those observed for Trolox, and more active than those of BHT and hesperidin. The β ‐glucosidase and α ‐amylase produced during fermentation were mainly responsible for mobilisation of the phenolics. CONCLUSION Our results demonstrate that fermented soy germ has the potential to be a good dietary supplement for prevention of oxidative stress‐related diseases, and the solid‐state bioprocessing strategy could be an innovative approach to enhance the antioxidant activity of soy germ. © 2014 Society of Chemical Industry