• Korean Journal of Microbiology
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• v.48 no.4
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• pp.298-304
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• 2012

Among 63 Bacillus strains grown at $60^{\circ}C$ from sixteen samples of homemade Korean soybean paste, one strain was selected for producing the thermostable protease. The isolate has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. Culture filtrate of the isolate showed maximal protease activity at the reaction condition of $60-65^{\circ}C$ and pH 11. The culture filtrate retained more than 87% of initial protease activity after incubation for 30 min at $60^{\circ}C$ without substrate. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon sources, metal ions and phosphate were examined for protease production of the isolate. Lactose and soytone peptone were the most effective carbon and nitrogen source for the enzyme production. After the late logarithmic growth phase the isolate began to produce the protease, and the maximum protease productivity was reached to 550 unit/ml in the optimized medium consisting of lactose (3%), soytone peptone (1.5%), $MgSO_4$ (0.1%), $K_2HPO_4$ (0.03%), and $KH_2PO_4$ (0.03%) at 28 h of incubation.

• Food Science and Preservation
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• v.16 no.3
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• pp.348-354
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• 2009

We examined the quality characteristics of soybean paste prepared using Bacillus subtilisDH3, which expresses high levels of protease, and deep-sea water. The protease activity of Doenjang prepared with Bacillus subtilis DH3 was $278.83{\pm}1.68$ units/mL/min. Protease and angiotensin-converting enzyme (ACE) inhibition activities increased with aging, for up to 30 days. The electron-donating ability (EDA) of Doenjang PD(Doenjang fermented with protease prodncing B. Subtilis DH3) was $61.27{\pm}0.42%$, whereas Doenjang M (traditional Doenjang fermented with meju and salt) had a lower value of $14.47{\pm}0.41%$. The mineral content of Doenjang PD was higher than that of Doenjang M. The overall acceptability of Doenjang PD was better than that of Doenjang M.

• Preventive Nutrition and Food Science
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• v.11 no.2
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• pp.127-132
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• 2006

Bacillus sp. strain K-l, which produces a strong fibrinolytic enzyme, was isolated from chongkukjang, a traditional Korean fermented soybean paste. The fibrinolytic enzyme was purified from chongkukjang base by using ammonium sulfate fractionation and chromatographic techniques. Purified enzyme, CK K-1 was demonstrated to be homogeneous by SDS-PAGE and isoelectric focusing electrophoresis, and has molecular mass of a 12.4 kDa and a pI of 8.0. The optimal reaction pH value and temperature were 8.0 and $40^{\circ}C$, respectively. Phenyl-methyl-sulfonyl-fluoride (PMSF; serine protease inhibitor), ethylene-diamine-tetra-acetic acid (EDTA; metallo protease inhibitor), copper ion, ferric ion and lead ion inhibited the enzyme activity. These results indicated that the fibrinolytic enzyme is a metallo-serine protease and different from nattokinase and chongkukjangkinase.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.924-933
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• 1998

Kochujang, fermented hot pepper-soybean paste, was prepared by two common varieties of red pepper and natural fermented (NF) or pure cultured (PC) meju (soybean mass that is soaked, steamed, mashed and fermented by natural microflora or pure strain) and monitored their taste related component, enzyme activity and microflora during fermentation at $25^{\circ}C$ for 120 days for confirming possibility of kochujang fermentation control. The reducing sugars, amino type nitrogen (reference quality factor) and amino acid content in PC kochujang were 11.4%, 0.58% and 1,372.9 mg% respectively, 7.1%, 0.42% and 1,038.7 mg% in NF kochujang. It is concerned higher ${\alpha}-{\;}and{\;}{\beta}-{\;}amylase$ and, acid and neutral protease in PC kochujang during fermentation. The meju fermented by selected pure strain (A. oryzae CBU) can be applied to produced better quality of kochujang instead of natural meju.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.137-142
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• 2007

This study was carried out to observe the antioxidant and angiotensin converting enzyme (ACE) inhibitory activity of susijang (Korean traditional fermented soy food). The antioxidant activity of susijang was measured by using TEAC (trolox equivalent antioxidant capacity) assay. In addition contents of isoflavones, phenolic acids and amino acids were determined. TEAC values of chungkukjang and susijang were significantly higher than those of yellow soybean (p<0.05). The contents of isoflavones (genistein, daidzein) were found to be significantly higher in chungkukjang and susijang than yellow soybean. The susijang showed high content of free amino acids and phenolic acids. ACE inhibitory activity of susijang was significantly higher than those of chungkukjang and yellow soybean, particularly of 70% ethanol extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.47-53
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• 2010

Bacteria strains with high activities of extracellular enzymes (protease, fibrinolytic enzyme, amylase, cellulase, and lipase) were isolated from Jeju traditional fermented soybean paste (Doenjang), and characterized by 16S rRNA gene sequence analysis and physiological properties. Protease activities were higher in JR14, JR19, JR25, JR32, JR38, JR47, and JR64 than Bacillus subtilis KCCM 12027 (standard strain). Amylase activities were shown in JR6, JR25, JR38, JR56 and JR81, while not in KCCM12027. Cellulase activities were higher in JR6, JR14, JR48, and JR65 than those of other isolated strains and KCCM 12027 whereas lipase activities were the higher in JR-14 and JR-48. Thrombolytic activity in JR19 with high hemolysis activity were 192% compared with that of plasmin as a positive control. Zymogram analysis indicated that the thrombolytic active strains had 4~5 bands in the molecular weight range of 25~75 kDa. Gene sequence analysis of rRNA revealed that the isolated stains had 99% homology with Bacillus species, and the thrombolytic active stain JR19 was B. stratosphericus $41KF2a^T$.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.516-520
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• 1996

This research is based on the literature and field study of buddhist the kinds; of temple kimchi and of the way how it is made. It has been spread by word of mouth to be 50 kinds of kimchi. But, according to this study. 24 kinds of kimchi or so are found to be present. The kinds of buddhist temple kimchi differ according to each area, Its condition of climate and materials mainly produced in that area. The distinctive features of buddhist temple kimchi are to use kamcho, soysauce and soybean paste instead of sugar and salted fishes. At conclusion the further study is necessary to preserve and inherit the remaining kinds of kimchi.

• The Korean Journal of Mycology
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• v.23 no.2 s.73
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• pp.161-175
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• 1995

Meju is a raw material used to make Korean soy sauce (Kanjang) and soybean paste (Doenjang), both of them rich in plant protein. The twenty-nine fungal and a bacterial species were identified from twenty-three traditionally homemade meju cakes. Out of them, only a few species were found to be involved in the actual fermentation process of meju; The other species were contaminants during the improper subprocesses of meju fermentation. The fungal floral successions were observed to be related to two physical and biochemical changes of meju cakes during meju fermentation: drying and heat releasing processes. The zygomycetous fungi were first observed to exist mainly during the first stage. Scopulariopsis brevicaulis was observed to grow on the surface of meju cakes and then to coexist with Bacillus megatrium in the inner part of meju cakes during the second stage. Based on the biochemical tests, the proteases secreted by the different microorganisms were involved in the degradation of soybean proteins with a mutual relationship. Also, zygomycetous fungi were speculated to be important microorganisms for inducing the second stage in the traditional Korean homemade meju.

• Mycobiology
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• v.42 no.4
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• pp.368-375
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• 2014

Red ginseng (Panax ginseng), a Korean traditional medicinal plant, contains a variety of ginsenosides as major functional components. It is necessary to remove sugar moieties from the major ginsenosides, which have a lower absorption rate into the intestine, to obtain the aglycone form. To screen for microorganisms showing bioconversion activity for ginsenosides from red ginseng, 50 yeast strains were isolated from Korean traditional meju (a starter culture made with soybean and wheat flour for the fermentation of soybean paste). Twenty strains in which a black zone formed around the colony on esculin-yeast malt agar plates were screened first, and among them 5 strains having high ${\beta}$-glucosidase activity on p-nitrophenyl-${\beta}$-D-glucopyranoside as a substrate were then selected. Strain JNO301 was finally chosen as a bioconverting strain in this study on the basis of its high bioconversion activity for red ginseng extract as determined by thin-layer chromatography (TLC) analysis. The selected bioconversion strain was identified as Candida allociferrii JNO301 based on the nucleotide sequence analysis of the 18S rRNA gene. The optimum temperature and pH for the cell growth were $20{\sim}30^{\circ}C$ and pH 5~8, respectively. TLC analysis confirmed that C. allociferrii JNO301 converted ginsenoside Rb1 into Rd and then into F2, Rb2 into compound O, Rc into compound Mc1, and Rf into Rh1. Quantitative analysis using high-performance liquid chromatography showed that bioconversion of red ginseng extract resulted in an increase of 2.73, 3.32, 33.87, 16, and 5.48 fold in the concentration of Rd, F2, compound O, compound Mc1, and Rh1, respectively.

• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.324-333
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• 2010

Off-flavor in foods and in raw materials is quite concerning, as it could signify deeper-rooted problems. Methods of reduction of "off-flavors" in traditional food such as Cheonggukjan and Kimchi, and in raw materials of soybean paste were studied by means of a literature review. It was found that the major components of "off-flavor" were due to butyric acid, valeric acid, alkylpyrazines, ammonia, and sulfides for Cheonggukjang, and for Kimchi were sulfur containing components such as methyl allylsulfide, dimethyl disulfide, diallyl disulfide, methyl allyl trisulfide, methyl 2-propenyldisulfide, dipropenyldisulfide. There is a demand for a scientific and systematic approach in overcoming the "off-flavor" problem. Nutritional aspects and safety should be considered. Several methods have been attempted, such as masking, binding, improving cooking process, inhibiting rancidity, and controlling the growth of micro-organism. Methods of masking were the most frequently ones used for the reduction of "off-flavor", and in some cases, othertechniques were additionally applied. The masking method would be useful in the reduction of "off-flavor" in traditional Korean foods, i.e. Cheonggukjang, Kimchi, as well as in new product development.