• Applied Biological Chemistry
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• v.43 no.1
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• pp.29-33
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• 2000

This study was carried out to investigate the effect of glutaminase added to Doenjang, Kochujang and Kanjang in manufacturing. The consequential changes of L-glutamic acid and amino nitrogen contents were periodically analysed during aging. L-Glutamic acid contents in Kochujang, Doenjang and Kanjang aged for 45 days increased to 671.8%, 298.1% and 193.4% with glutaminase and also increased to 363.1%, 159.2% and 35.7% as compared with those without glutaminase. The 0.01% addition of glutaminase to Kochujang made L-glutamic acid content increased more than 3 times. The increase ratio of amino nitrogen was 216%, 120.8% and 84.5% in Kochujang, Kanjang and Doenjang with glutaminase which aged for 45 days, respectively. The effect of glutaminase added was the greatest in Kochujang. It increased to 35.7%, 8.4% and 40.3% as compared with those without glutaminase. The results of sensory evaluation showed that the products were favorably affected in taste, flavor and acceptability by glutaminase added.

• Korean Journal of Microbiology
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• v.55 no.2
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• pp.131-142
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• 2019

The primary objective of this study was to determine the content of biogenic amines in Korean traditional fermented soybean pastes (doenjang) and to isolate potential probiotic Bacillus sp. with the ability to inhibit biogenic amines accumulation. There were significant differences in the bacterial cell counts, pH value, titratable acidity, salinity, and biogenic amine content between the samples. Among Bacillus strains isolated from doenjang, Bacillus (B.) licheniformis DB102, B. subtilis DB203, B. stearothermophilus DB206, Bacillus sp. DB209, Bacillus sp. DB310, B. coagulans DB311, B. cereus DB313, B. amyloliquefaciens DB714, Bacillus sp. DB917, B. cereus DB 915, B. subtilis DB1020, and Bacillus sp. DB1022 were found to be able to produce biogenic amines. On the other hand, biogenic amine-degrading strains were identified as Bacillus sp. DB403, Bacillus sp. DB407, B. subtilis DB517, B. licheniformis DB612, and B. subtilis DB821. In particular, Bacillus sp. DB407 and B. subtilis DB821 showed probiotic properties including tolerance to artificial digestive juices, adherence to intestinal epithelial cells, resistance to antibiotics, and antibacterial activity against biogenic amine-producing strains. In conclusion, the two probiotic Bacillus strains may be considered as the suitable starter for manufacture of fermented soybean foods with low biogenic amines content.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.339-346
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• 2014

A bacterial strain was isolated from homemade doenjang (Korean fermented soybean paste) as a producer of the extracellular ${\beta}$-galactosidase, capable of hydrolyzing lactose to liberate galactose and glucose residues. The isolate YB-1414 has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. The production of ${\beta}$-galactosidase by B. licheniformis YB-1414 reached maximum levels of 6.2 U/ml in culture medium containing wheat bran (1%) and yeast extract (2.5%) as carbon and nitrogen sources, respectively. Particularly, the insoluble fraction was more effective for ${\beta}$-galactosidase production than the soluble extract of wheat bran. The enzyme exhibited maximum activity for hydrolysis of para-nitrophenyl-${\beta}$-D-galactopyranoside (pNP-${\beta}Gal$) under reaction conditions of pH 6.0 and $55-60^{\circ}C$. Its hydrolyzing activity for pNP-${\beta}Gal$ was drastically decreased by the addition of low concentrations of galactose, but only slightly decreased by glucose, with 85% of maximal activity in the presence of 400 mM glucose.

• Food Science and Preservation
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• v.21 no.5
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• pp.627-635
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• 2014

We investigated the changes in the quality characteristics of Doenjang with low salt contents (6, 8, 10, and 12%) and 10% garlic. The Doenjang was analyzed at an interval of a week during its fermentation for six weeks, at room temperature. Its L color gradually decreased, but its a and b colors did not change significantly. Its salinity increased by about 1% after six weeks. In contrast, immediately after its preparation, its pH was gradually decreased and its acidity was increased for the fermentation. The reducing sugar was significantly increased from 1.34~1.88 g/100 g immediately after its preparation to 7.25~9.13 g/100 g after six weeks, which was higher as the salt concentration decreased. The amino-type nitrogen doubled from 100~130 mg% at 0 week to 210~290 mg% at six weeks, which were lower with the higher salt concentrations. The growth curve of the Bacillus fermentation strains of Doenjang increased to two weeks but gradually decreased since, and the growth of the Bacillus was favorable for up to two weeks in the Doenjang with 10% and 12% salt added. Otherwise, the yeast was reduced rapidly during the early fermentation of the Doenjang, and slightly changed after three weeks of fermentation. The results of this study showed that the reducing sugar and amino-type nitrogen contents of the low-salt garlic Doenjang were higher with the lower salt dose, and the physicochemical quality of the 6%-salt Doenjang was not significantly affected. Thus, we suggest that low-salt Doenjang can be manufactured with the addition of 6% salt and 10% garlic.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.115-120
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• 2008

To develop a new Gugija(Lycium chinensis Mill) product having increased value, the physiological functionality of various commercial Gugija products were investigated. In addition, an in vivo study was performed using spontaneous hypertensive rats(SHR) to examine the anti-hypertension effects of products. The results showed that antioxidant activity was highest in the methanol extract of Gugija leaf pickle(97.7%), and anti-hypertensive angiotensin I -converting enzyme(ACE) inhibitory activity was 80.4% in Gugija doenjang(soybean paste) water extract. Anti-cholesterolemia HMG-CoA reductase inhibitory activity was highest in the methanol extract of Gugija rice cake(66.1 %). However, SOD-like activity was below 30% in most products; and fibrinolytic activity was not detected or was very weak. Ultimately, we selected Gugija tea and Gugija wine as superior anti-hypertensive Gugija products, and subsequent in vivo testing was performed using SHR, comparing the tea and wine to Gugija fruit. Among them, the Gugija fruit demonstrated the best anti-hypertension effects in SHR.

• 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.

• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.77-84
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• 1998

To evaluate food consumption patterns of first generation Korean-American in Hawaii, questionnaires were developed using sociodemographic questions and food frequency questionnaire, which included 139 food items most often consumed among Korean foods and American foods. The questionnaires surveyed 157 first generation Korean-Americans in Hawaii. Mean daily servings for the first generation Korean-Americans were calculated for 139 food items combined into 41 food groups based on similarity in nutrient composition and serving size. The food groups which were consumed in amounts over one serving per day for all subjects were rice, Kimchi , non-citrus fruit , vegetables, organge/green vegetables. oil. margarine and coffee/tea. All subjects consumed less than one serving of hotdogs, hamburgers, pizza and pancakes per week(0.14 serving per day). The most notable characteristic of food consumption for first generation Korean-Americans was that they consumed more Korean food such as rice, Kimchi, soybean paste(Deenjang), soybean curd and seaweed than American foods. Compared with other groups based on age and gender, younger men showed significantly(p<0.05) more frequent consumption of beef/pork, sausages /hams /bacons and hambergers. Older men were significantly(p<0.05) more likely to consume Doenjang and less likely to consume pizza and hamburgers. Daily servings were below the recommended level for thegrains /bread/cereals group and fats/oils/sweets group for all subjects . Fruits/vegetables group servings exceeded the recommeded 5 daily servings for younger men. In correlations of daily servings of selected foods among Korean foods and American food with sociodemographic characteristics, this study showed that the older the subjects and the shorter the stay in Hawaii, subjects were more likely to consume Kroean foods.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.299-304
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• 2017

Biogenic amines such as histamine, tyramine, cadaverine, and putrescine may have detrimental effects on consumers' health; therefore, they must be considered hazardous substances in foods. In recent years, the application of microorganisms that can degrade biogenic amines has become an emerging method for reducing the amount of these amines in foods. Primarily, Bacillus sp. BCNU 9171 was isolated from Doenjang, a Korean traditional fermented soybean paste. The inhibitory effects of the cell-free supernatant (CFS) of Bacillus sp. BCNU 9171 on biogenic amine production by 4 amine-positive food pathogenic bacteria were investigated using high performance liquid chromatography (HPLC). Our results showed that 4 different CFS concentrations-10% [1 ml CFS + 9 ml histidine decarboxylase broth (HDB)], 25% (2.5 ml CFS + 7.5 ml HDB), 50% (5 ml CFS + 5 ml HDB), and 75% (7.5 ml CFS + 2.5 ml HDB)-reduced the biogenic amine production up to 87% compared with that of the control without CFS. These results suggested that it is advisable to use Bacillus sp. strain BCNU 9171 as a starter organism for the manufacture of fermented foods and to ensure food safety since it prevents the accumulation of high amounts of biogenic amines in fermented foods by amine-positive bacteria.

• Journal of Life Science
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• v.17 no.8 s.88
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• pp.1121-1128
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• 2007

The fruits of Zanthoxylum piperitum are known as having various physiology vitality, and the abstraction ingredient of the pericarp is also known as having strong antibiotic activities against various bacteria. Therefore, this study was carried out to estimate the effect of physiology vitality when the abstraction ingredient of Z. piperitum was added in soy sauce(Chopi-kanjang) and soybean paste(Chopi-doenjang). For the antibiotic activity against the pathogens of sitotoxism such as Staphylococcus aureus, Salmonella typhimurium, Vibrio parahemolyticus, Escherichia coli 0157:H7, the extracts of the Chopi-kanjang was added 1%, 2%, 4% pericarp of Z. piperitum in the manufacturing process of soy source. According to the results, the growth of E. coli 0157:H7 and V. parahemolyticus were respectively inhibited as 70% and 50% by the Chopi-kanjang added 2% of the ingredient. For the antibiotic effects of the aforementioned Chopi-kanjang against Sal. typhimurium and Sta. aureus, the growth of those pathogens was also inhibited between 40% and 60% according to the manufacturing period of Chopi-kanjang. It was confirmed that the antibiotic activity using the mixture of the abstraction ingredient and Chopi-doenjang was lower than those of Chopi-kanjang. In order to estimate the anticancer activity using by caspase-3 activity, the mixture of the abstraction ingredient of the pericarp of Z. piperitum and Chopi-kanjang was treated to leukemia cells. According to the results, the activities of caspase-3 using the mixture added 1%, 2% and 4% of the abstraction ingredient were respectively increased as much as 4, 12, 15 times comparing with the control which was treated with the soy source only. It could be that the mixture of the abstraction ingredient of the pericarp of Z. piperitum and soy source induced apoptosis, and the mixture of the abstraction ingredient and soybean paste had no effect on the activity of caspase-3. In order to find out the death of the aforementioned cells caused by necrosis or apoptosis, DNA fragmentation in the cell was examined. U-937 cells showed apoptotic DNA fragmentation in the incubation with Chopi-kanjang extract.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.730-737
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• 2006

High performance liquid chromatographic methods for the simultaneous determination of 12 biogenic amines were developed and contents of biogenic amines in 23 varieties of Korean commercial fermented food were analyzed. Dansyl derivatives of biogenic amine were very stable and had good peak resolution. Except agmatine, the recovery of biogenic amines from soybean paste with extraction of 0.1 N HC1 added biogenic amines to soybean paste was greater 85%. The calibration curve showed good linearity over a concentration range up to 50 ${\mu}g/mL$. In the determination of biogenic amine level in Korean commercial fermented foods, doenjang and chungkukjang (fermented soybean pastes), soy sauce, anchovy and pacific sand lance liquid jeotkal (fermented fish sauce products), and cabbage kimchi had high level biogenic amines. Especially, traditional doenjang had a histamine (HIS) level of 952.0 mg/kg, a tyramine (TYR) level of 1,430.7 mg/kg. Most cheese had low level of biogenic amines, but one Gouda cheese had a tyramine (TYR) level of 97.5 mg/kg. A low level of biogenic amines was detected in wines, beer, yoghurt, and sausage. Putrescine (PUT), cadaverine (CAD), tryptamine (TRY), histamine (HIS), tyramine (TYR), and 2-phenylethylamine (PHE) were mainly formed in fermented foods by the action of microorganism, so their levels were high with a range. On the other hand, spermidine (SPD), spermine(SPM), serotonin (SER), noradrenaline (NOR), and dopamine (DOP) were formed originally via biosynthesis with consequent low level.