In this study, soy-powder yogurt (SPY) with enhanced levels of γ-aminobutyric acid (GABA) and isoflavone aglycone was produced from sprouting high-protein soybeans (HPSs). The fermented steam-HPS sprouts (0 to 4 cm) were fermented (72 h) with Lactobacillus brevis, and the total free amino acids (FAAs) of the formed mixtures were determined to be 79.53, 489.93, 877.55, 780.53, and 979.97 mg/100 mL in the fermented HPS (FHPS), and the fermented steam-HPS with 0 cm (FSHPS-0), 1 cm (FSHPS-1), 2 cm (FSHPS-2), and 4 cm sprouting lengths (FSHPS-4), respectively. The levels of glutamic acid (GA) and GABA were observed to be the highest, 100.31 and 101.60 mg/100 mL, respectively, in the unfermented HPS (UFSHPS-1, 1 cm) and FSHPS-1 sprouts, respectively. Moreover, the total contents of the isoflavone glycoside form decreased proportionally to the increasing total levels of isoflavone aglycones after fermentation in FSHPS-0, FSHPS-1, FSHPS-2, and FSHPS-4. The levels of isoflavone aglycones were detected as 350.34, 289.15, 361.61, 445.05, and 491.25 μg/g in FHPS, FSHPS-0, FSHPS-1, FSHPS-2, and FSHPS-4, respectively. While FSHPS-1 exhibited the highest DPPH (63.28%) and ABTS (73.28%) radical scavenging activities, FSHPS-4 contained the highest isoflavone aglycone ratio (81.63%). All in all, the FSHPS-1 mixture prepared in this study exhibited high GABA content and functional prosperity, thereby making it suitable for potential applications in the soy-dairy industry.

In this study, contetnts of phenolic acid and isoflavone, and biological activities of soy sauce were compared the soy sauce added bitter melon powder (BMPs). After the fermentation, pHs were decreased from 5.83 (0% BMP), 5.47 (5% BMP), and 5.32 (10% BMP) to 5.28, 5.36, and 5.16 at 90 days, whereas the acidities of soy sauce were increased from 0.06%, 0.07%, and 0.09% to 0.30%, 0.28%, and 0.36% at 90 days, respectively. In addition, the salinities of soy sauce were decreased, while viable cell numbers including Bacillus and yeast were increased. The contents of total phenolic, isoflavone-aglycone, and phenolic acid and antioxidant and α-glucosidase inhibition activities were significantly increased for 90 days, while the isoflavone-glycoside contents were decreased. In Particular, soy sauce with 10% BMP at 90 days showed the highest contents of glutamic acid (GA, 9,876.09 mg/100 mL) and γ-aminobutyric acid (GABA, 325.02 mg/100 mL) contents than among other samples. Additionally, the radical scavenging activities (DPPH, ABTS, ⦁OH, and FRAP) and α-glucosidase inhibition activities of soy sauce with 10% BMP at 90 days were shown to be high 96.07%, 97.27%, 59.47%, 1.98%, and 79.96%, respectively.

1. Polyacrylamide gel electrophoresis를 이용하여 국내외 재래종과 야생종 대두 계통들의 trypsin inhibitor의 변이를 규명하기 위하여 본 시험이 시도되었으며 1706계통의 한국산 재래종과 103계통의 한국 야생종콩, 그리고 167계통의 외래 재배종과 71계통의 외국 야생종 대두가 공시되었다. 2. Trypsin inhibitor를 함유하지 않은 ti/ti형과 Ti c/c형은 한국 재래종에서만 발견되었으며, Ti* c형을 Hymowitz도 일본 대두품종에서 보고한 바 있으나 그도 이 계통은 한국 도래종일 가능성이 크다고 보고 한 바 있다. 3. 한국기원의 콩에서 trypsin inhibitor에 관한 이형접합형의 출현빈도가 외국 기원 콩 계통에서 보다 비교적 높았으며, 재래종에서 3.6%(N=61)와 야생종에서 9.7%(N=10)이었으며 종합적으로 보아 중국, 일본 등의 대두에 비해 한국 기원의 콩이 가장 큰 변이를 나타내고 있음을 확인하였다.