Preparation of fermented sugar-soaked black soybean snacks (FSBSS) and characterization of their quality changes

Fermented sugar-soaked black soybean snacks (FSBSS) were prepared using optimized conditions at 2 times sugar soaking process to give a desirable form and texture after fermentation with Lactobacillus plantarum (LP) and Bacillus subtilis (BS) for 48 h. The prepared FSBSS showed higher total polyphenol and flavonoid contents than an unfermented (NF) sample; total isoflavone content increased approximately 31 and 17% (LP and BS, respectively), as compared to NF. γ-Aminobutyric acid was also contributed by LP and BS, indicating significantly higher contents of 16. 9 and 21. 6 mg/g (LP and BS, respectively) compared to NF (15. 2 mg/g). Moreover, the FSBSS showed antioxidant activities on DPPH, superoxide, and hydroxyl radicals as compared to NF. Based on the results, the newly developed FSBSS using solid-fermentation indicate a useful and convenient way to replace traditional soybean products from the standpoint that also provides an easy means to supply high nutritive and functional properties.