• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.303-310
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• 2016

In this study, doenjang samples were prepared with different types of salts (12%, w/w): purified salt (PS), 3-year aged solar salt (SS3), 1-year aged solar salt (SS1), and bamboo salt melted 3 times (BS). Whole-soybean mejus were fermented with starters consisting of 2 Bacillus strains, a yeast, and a fungus (starter doenjang), and control mejus were fermented with organisms present naturally in rice straw (non-starter doenjang). The whole-soybean mejus were dried, and then mixed with cooked soybeans and the respective salts. The doenjang samples were fermented for 13 weeks at 25℃. The protease (acid, neutral, and alkaline) activities, fibrinolytic activities, and antioxidant capacities of the samples were examined every week. BS doenjang showed the highest acid protease (6.46 ± 0.20 unit/g) and fibrinolytic activities (0.61 unit/ml). Among the starter doenjang samples, those made with SS and BS showed the highest total phenolic contents after 91 days of fermentation. For antioxidant activities, SS3 doenjang showed higher activities than the other doenjang samples, as evaluated by ABTS, DPPH, and FRAP assays. These results suggest that solar salt, especially aged for 3 years, is better than purified salt in terms of producing better functionalities of doenjang.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.12
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• pp.1915-1923
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• 2013

The aim of this study is carried out to evaluate the fermentation characteristics and increased functionality when doenjang was prepared with bamboo salts. Grain type mejus were fermented with mixed starter cultures of Aspergillus oryzae, Bacillus subtilis, and Lactococcus lactis. These mejus were mixed with different kinds of salts-purified salt (PD), sea salt (SD), one-time baked bamboo salt ($1{\times}BD$), three-time baked bamboo salt ($3{\times}BD$), and nine-time baked bamboo salt ($9{\times}BD$)- when doenjangs were prepared. For doenjang fermentation period of 8 weeks at $37^{\circ}C$, the fermentation characteristics of all the groups were compared. The amino type nitrogen content and enzyme activities (protease and ${\alpha}$-amylase) in the samples were significantly increased. In DPPH radical scavenging activities and hydroxyl radical scavenging activities, $9{\times}BD$ (47% and 69%) showed the highest scavenging activities compared to PD (40% and 49%), SD (42% and 57%), $1{\times}BD$ (42% and 64%) and $3{\times}BD$ (45% and 65%) (P<0.05). The anticancer effects of doenjang in HT-29 cancer cells indicated all the groups, especially doenjang prepared with bamboo salts were higher than the others (P<0.05). Apoptosis related genes of Bax and Bcl-2, as well as inflammation related genes of iNOS and COX-2 were regulated by the treatment of doenjangs in HT-29 cancer cells. SD, $1{\times}BD$, $3{\times}BD$, and $9{\times}BD$ increased the expression level of Bax and decreased the expression level of Bcl-2, iNOS, and COX-2. These results suggest that sea salt and bamboo salt especially bamboo salt could improve fermentation characteristics and functionality of doenjang and play an important role in regulating apoptosis and inflammation related genes in cancer cells.

• Journal of Microbiology and Biotechnology
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• v.29 no.2
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• pp.191-199
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• 2019

We inoculated different combinations of three starter candidates, Bacillus licheniformis, Staphylococcus succinus, and Tetragenococcus halophilus, into sterilized soybeans to predict their contributions to volatile compound production through soybean fermentation. Simultaneously, we added NaCl to soybean cultures to evaluate its effect on the volatile compounds profile. Cells in soybean cultures (1.5% NaCl) nearly reached their maximum growth in a day of incubation, while cell growth was delayed by increasing NaCl concentrations in soybean cultures. The dominance of B. licheniformis and S. succinus in the mixed cultures of three starter candidates switched to T. halophilus as the NaCl concentration increased from 1.5% to 14% (w/w). Seventeen volatile compounds were detected from the control and starter candidate-inoculated soybean cultures with and without the addition of NaCl. Principal component analysis of these volatile compounds concluded that B. licheniformis and S. succinus made major contributions to producing a specific volatile compound profile from soybean cultures where both species exhibited good growth. 3-Hydroxybutan-2-one, butane-2,3-diol, and 2,3,5,6-tetramethylpyrazine are specific odor notes for B. licheniformis, and 3-methylbutyl acetate and 2-phenylethanol are specific for S. succinus. Octan-3-one and 3-methylbutan-1-ol were shown to be decisive volatile compounds for determining the involvement of S. succinus in the soybean culture containing 7% NaCl. 3-Methylbutyl acetate and 3-methylbutan-1-ol were also produced by T. halophilus during soybean fermentation at an appropriate level of NaCl. Although S. succinus and T. halophilus exhibited growth on the soybean cultures containing 14% NaCl, species-specific volatile compounds determining the directionality of the volatile compounds profile were not produced.

• Food Science of Animal Resources
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• v.43 no.5
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• pp.877-888
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• 2023

We studied the proteolysis and conducted a sensory evaluation of fermented sausages using strains derived from Kimchi [Pediococcus pentosaceus-SMFM2021-GK1 (GK1); P. pentosaceus-SMFM2021-NK3 (NK3)], Doenjang [Debaryomyces hansenii-SMFM2021-D1 (D1)], and spontaneous fermented sausage [Penicillium nalgiovense-SMFM2021-S6 (S6)]. Fermented sausages were classified as commercial starter culture (CST), mixed with GK1, D1, and S6 (GKDS), and mixed with NK3, D1, and S6 (NKDS). The protein content and pH of GKDS and NKDS were significantly higher than those of CST on days 3 and 31, respectively (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the NKDS had higher molecular weight proteins than the GKDS and CST. The myofibrillar protein solubility of the GKDS and NKDS was significantly higher than that of the CST on day 31 (p<0.05). The GKDS displayed significantly higher pepsin and trypsin digestion than the NKDS on day 31 (p<0.05). The hardness, chewiness, gumminess, and cohesiveness of the GKDS were not significantly different from those of the CST. The GKDS exhibited the highest values for flavor, tenderness, texture, and overall acceptability. According to this study, sausages fermented using lactic acid bacteria (GK1), yeast (D1), and mold (S6) derived from Korean fermented foods displayed high proteolysis and excellent sensory evaluation results.

• Preventive Nutrition and Food Science
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• v.8 no.1
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• pp.54-60
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• 2003

To develop a functional chungkookjang; the anticancer effects of chungkookjangs prepared with different varieties of soybeans, starters, fermentation periods and seasoning additive ratios; were studied against AGS human gastric adenocarcinoma cells using the MTT assay, at different stages chungkookjang processing. The chungkookjang samples exerted different antiproliferative effects according to the variety of soybeans used. The chungkookjangs manufactured with soybean var. manrikong exhibited the highest cytotoxicity against AGS human cancer cells. The chungkookjangs fermented with rice straw and B. licheniformis strongly inhibited the growth of the AGS human cancer cells. All fermented chungkookjangs had a strong inhibitory effect on the growth of the cancer cells; however, the non-fermented soybean (chungkookjang) showed a low inhibition rate. The fermented chungkookjangs mixed with red pepper powder (RPP) and garlic exhibited strong antiproliferative effect against the cancer cells, and chungkookjang prepaved with 1.1 % RPP and 1.1 % garlic showed the highest cytotoxicity against the cancer cells. The functional chungkookjang fermented with soybean variety of manrikong and B. licheniformis for 3 days at 4$0^{\circ}C$ and then mixed with 7.9% salt, 1.l% RPP and 1.1% garlic, exhibited a higher antiproliferative effect than the chungkookjangs prepared by traditional or modified methods, according to the MTT assay. The functional chungkookjang exhibited a similar anticancer effect to the traditional doenjang. These results indicate that the fermentation period and the ratio of seasoning additives, as well as the variety of soybeans and starter cultures may affect the degree of the anticancer effect of chungkookjang.