• Journal of Life Science
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• v.26 no.10
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• pp.1113-1120
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• 2016

Two bacterial strains producing extracellular man nanase were isolated from doenjang, a traditionally fermented soybean paste in Korea. The isolates, WL-6 and WL-11, were identified as Bacillus subtiis on the basis of their 16S rRNA gene sequences, morphological, and biochemical properties. Two genes encoding the mannanase of both B. subtilis WL-6 and B. subtilis WL-11 were each cloned into Escherichia coli, and their nucleotide sequences were determined. Both mannanase genes consisted of 1,086 nucleotides, encoding polypeptides of 362 amino acid residues. The deduced amino acid sequences of the two WL-6 and WL-11 mannanases, designated Man6 and Man11, respectively, differed from each other by eight amino acid residues, and they were highly homologous to those of mannanases belonging to the glycosyl hydrolase family 26. The 26 amino acid stretch in the N-terminus of Man6 and Man11 was a predicted signal peptide. Both Man6 and Man11 were localized at the level of 94–95% in an intracellular fraction of recombinant E. coli cells. The enzymes hydrolyzed both locust bean gum and mannooligosaccharides, including mannotriose, mannotetraose, mannopentaose, and mannohexaose, forming mannobiose and mannotriose as predominant products. The optimal reaction conditions were 55°C and pH 6.0 for Man6, and 60°C and pH 5.5 for Man11. Man11 was more stable than Man6 at high temperatures.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.84-97
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• 2016

Isolates from Korean fermented soybean paste were identified as Enterococcus faecium SBP12, Pediococcus halophilus SBP20, Lactobacillus fermentum SBP33, Leuconostoc mesenteroides SBP37, Pediococcus pentosaceus SBP41, Lactobacillus brevis SBP49, Lactobacillus acidophilus SBP55, and Enterococcus faecalis SBP58 according to conventional morphological and biochemical characteristics, carbohydrate fermentation profiling, and 16S rRNA sequence comparison. Strain SBP20, SBP33, SBP49, and SBP55 showed very resistance to simulated gastric and intestinal juices with final populations exceeding 6 log CFU/ml, whereas cells of SBP12 and SBP58 after exposure to low pH were dramatically decreased within 2 h. Among 4 strains having good tolerance to gastrointestinal conditions, the high adhesive ability to HT-29 cells, antibiotic resistance, and antimicrobial activity against food-borne pathogens Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 were observed with SBP49 and SBP55, therefore, these two strains were confirmed as putative probiotic candidates. There was no significant difference between the sourdoughs fermented with SBP49 and SBP55 with respect to the values of pH, total titratable acidity, and viable cell count. During sourdough fermentation, SBP49 strain produced significantly greater amounts of lactic acid than SBP55 strain, which secreted large quantities of hydrogen peroxide. SBP49 and SBP55 strains producing the antimicrobial substances such as lactic acid, hydrogen peroxide, and bacteriocin effectively inhibited B. cereus and S. aureus inoculated in the sourdough.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.472-477
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• 2001

The study was carried out to evaluate the sensory characteristics and physiological effect of Korean soybean Paste (doenjang) added with Japanese apricot, garlic and ginger, and samjang. Garlic doenjang was shown to have a good taste, odor and color, but ginger doenjang was worse in the taste, odor and color than control doenjang in sensory evaluation. Japanese apricot doenjang and garlic doenjang had high scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, of which the IC$\_$50/ values were 93 and 94$\mu\textrm{g}$/$m\ell$, respectively. Five kinds of doenjang revealed antimutagenic activity against N-methyl-N’-nitro-N-nitrosoguanidine (MNNG), and especially, samjang showed 83% inhibition at the concentration of 5mg/plate. Samjang exhibited a strong antimutagenic activity(79%) against aflatoxin B$_1$,(AFB$_1$) in Salmonella typhimurium TA100. Ginger-, garlic- and Japanese apricot doenjangs also had high inhibitory effects against AFB$_1$. and the inhibition rates were 75, 55 and 51%, respectively. In SOS chromotest. samjang showed the highest antimutagenicity against MNNG, with 64% inhibition rate. These results demonstrated that samjang has strong a antimutagenic effect against MNNG and AFB$_1$.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.901-906
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• 1997

In order to reproduce and improve quality of traditional kochujang, various raw materials were added to prepare kochujang by replacing part of the glutinous rice. Chemical composition, microbial characteristics and enzyme activities were investigated during fermentation. Crude protein and salt contents of kochujang did not change significantly during fermentation, but moisture contents increased linearly. The pH and titratable acidity of kochujang changed little in garlic added group. The viable cell counts of aerobic bacteria and yeasts in the kochujang increased until 60 days of fermentation and then decreased slowly except for the garlic added group in which they increased during the last period of fermentation. Aerobic bacterial count did not show any remarkable differences among the samples and slowly decreased after 60 days of fermentation. The activities of liquefying and saccharifying amylases decreased until 45 days, but increased at 60th day. Acidic protease activities of each group were strong during the initial period, but neutral protease showed the highest activity from the 30 to 45 days of fermentation. Protease activities increased by addition of soy sauce, Chinese matrimony vine and purple sweet potato.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.907-912
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• 1997

Physicochemical characteristics of kochujang prepared with various raw materials, were investigated during 90 days of fermentation to obtain information for the industrial production of traditional kochujang. Reducing sugar contents of kochujang increased until 60 days but slightly decreased thereafter, showing highest value for malt added group. Ethanol contents increased after 45 days and were highest in Chinese matrimony vine group, followed by purple sweet potato and malt added groups. Amino nitrogen contents increased until the 45 to 60 days of fermentation, but ammonia nitrogen contents did not change significantly during fermentation. Amino and ammonia nitrogen contents were higher in soy sauce and Chinese matrimony vine added groups. Water activities decreased slightly during fermentation and purple sweet potato added group was lowest among the groups. Consistency of kochujang decreased until the middle of the aging but after that it increased. Consistency of purple sweet potato and Chinese matrimony vine added groups were remarkably higher than that of the others. The color values tended to decrease slightly during fermentation. Purple sweet potato kochujang was low in the lightness, redness and yellowness. Results of sensory evaluation showed garlic and malt added kochujang were more acceptable than purple sweet potato added kochujang due to more desirable taste and color.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.784-788
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• 2001

Reliable data on the exposure of capsaicin, which evokes hot sensation in hot red pepper, are important prerequisites for studying biological functions of capsaicin in human body since its roles are controversial according to animal and epidemiological studies. To get accurate data, the use of urinary biomarkers was considered as a measure of internal exposure of capsaicin. After 2-day-capsaicin depletion five to six women in their 20's were instructed to eat 60 or 80 g/day hot red pepper soybean paste as a capsaicin source with meal which did not contain capsaicinoid, and to collect their urine separately. HPLC conditions were set to detect capsaicinoid and urinary metabolites at the same time. Most of capsaicinoid were excreted in the form of 4-hydroxy-3-methoxybenzoic acid in three subjects at the highest dose. This result suggests the oxidation of the 4-hydroxy3-methoxybenzaldehyde, the hydrolysis product of capsaicin, is the major metabolic pathway in the human body, whereas the reduction of the aldehyde is the major route in rats. However, neither any metabolite nor the parent compound was ever shown in two of the subjects reflecting large individual differences of capsaicin absorption and/or biotransformation.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.89-93
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• 2001

The quality characteristics of doenjangs added with squid internal organs were evaluated. The contents of moisture, salt and amino type nitrogen were similar among traditional doenjang and squid doenjang(I, II, III). But the color values were different. pH and peroxide value(POV) were high in squid doenjangs. Squid doenjang(I, II, III) contained much taurine($53.26{\sim}170.90\;mg%$) and ${\alpha}-aminobutyric$ acid($35.17{\sim}151.00\;mg%$) which were not detected in traditional doenjang. Also aspartic acid and glutamic acid related to palatable taste, threonine, serine and proline related to sweet tastes were much more in squid doenjangs. Contents of isoleucine and leucine related to bitter taste were similar with traditional doenjangs. Comparing with traditional doenjang, volatile flavor components in squid doenjangs had high ratio of esters such as ethylbutylether and aldehydes such as 2-propanal, 3-methylbutanal in contrast with low alcohols. Especially ethylbutylether, 2-propanol, 3-methyl-1-butanal, 2,6,10,14-tetramethyl-pentadecane, ethyllinoleate were only in squid doenjangs. From the sensory evaluation after 4 weeks, squid doenjang(II) added with 10% squid internal organs obtained the highest scores for taste as differing from traditional soybean paste and squid doenjang(I). But the total acceptability was higher in traditional doenjang because of strong fishy smell and dark color in squid doenjang. After 8 weeks squid doenjang(I, II) obtained high scores for taste and low scores for color and flavor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.605-610
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• 2001

To suppress the gas forming caused by some yeast in the pack of traditional kochujang prepared at Sunchang area, which is the most severe problem during distribution of commercial products, mustard or horseradish powder as natural preservatives was mixed to the ingredients of kochujang and left for fermentation in clay pot as commercial scale for 180 day. The composition changes including quality and gas formaing in the kochujang containing those additives were monitored physicochemically and organoleptically. The fermented kochujang containing those additives were monitored physicohemically and organoleptically. The fermented kochujang containing 0.6% of horseradish showed lower organic acid content than that of the control but amino type nitrogen content, which is one of the important quality reference of kochujang, was higher in the one containing 0.6% natural preservatives. No color changed in the kochujang containing mustard but L and a value were increased in the kochujang containing horseradish. No difference of free reducing sugars was showed by the addition of those natural preservatives and the addition of 0.6% horseradish to kochujang had completely stopped gas forming during fermentation. The overall quality of the kochujang containing 0.6% horseradish was superior than that of the other treatments.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.1
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• pp.86-96
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• 1984

In order to provide basic data for food processors and to improve eating habits and healthy diets, four primary tastes and hot taste threshold of Koreans, physio-chemical properties of foods and food preference were investigated. The results of this study were as follows; 1. The recognition threshold concentration of four primary tastes was 0.016 % of salt, 0.245${\sim}$0.249 % of sweet, 0.004${\sim}$0.008 % of sour and 0.008${\sim}$0.012 % of bitter. Threshold concentration of hot taste was 170,000${\sim}$600,000 Scoville Heat Unit(S.H.U.) 2. The most acceptable tastes were 0.3 % saltiness in 0.375 % broth(at $60^{\circ}C$), 6 % sweetness in 2 % instant coffee(at $60^{\circ}C$) and 19.3 sugar-acid ratio(16.8 brix/0.8736 % citric acid) in 100 % valencia orange juice(at $20^{\circ}C$). 3. The salt concentrations of soup were 1.127 % in average. S. H. U. (scale of hot taste) of soybean sprout soup and spinach bean paste soup ranged between 12,500 and 47,500 equivalent to oleoresin capsicum content of 1.990${\sim}$5.911 (mg %). 4. 'Jigae' (Korean style stew) was the most favorable food and it was revealed that the father influences the formation of his children's eating habits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1227-1234
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• 2011

We investigated the immunostimulatory effects of doenjang, a famous Korean traditional food made from fermented soybean paste, on the immunohistochemical reaction in the gastrointestinal (GI) tract and immune response in mice. Male C57BL/6N mice (6 weeks-old) were divided into 4 experimental diet treatment groups and a basal diet (control) group, and fed with different diets for 4 weeks. The immunoreactive density of $CD4^+/CD8^+$ lymphocytes were strongly stained in the jejunum and colon in Group III. The immunoreactivity of universal nitric oxide synthase (uNOS) was strongly stained in the myenteric plexus in the colon of all doenjang-fedgroups (I, II and III). The colonic immunoreactive density of protein kinase C-${\alpha}$ (PKC-${\alpha}$) was strongly increased in Groups II and III, while that of stem-cell factor (c-kit) was increased in colonic mucosa of all doenjang-fedgroups (I, II and III) and especially increased in the colonic muscle layer of Group III. These morphological and immunological results indicated that the intake of doenjang could improve the mucosal immune reaction, gastrointestinal motility, blood circulation in the GI tract, and the immuneactivity of the body. These results provide experimental evidence about the health benefits of doenjang.