• Food Science and Biotechnology
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• v.17 no.3
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• pp.519-526
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• 2008

To improve the quality of traditional kochujang, strains with high protease and amylase activity were isolated and identified from Sunchang traditional kochujang. Twenty-three strains strongly producing protease and 16 strains strongly producing $\alpha$- and $\beta$-amylase were isolated by using 1% isolated soy protein agar medium and 2% starch agar medium, respectively. Protease activities of the IA7, I5, and IA2 strain were 22.5, 21.2, and 20.6 unit/mL, respectively, and were higher than those of the other strains. Stains with high $\alpha$-amylase activity included K9 (967.8 unit/mL), K14 (828.3 unit/mL), K13 (662.5 unit/mL), K8 (601.5 unit/mL), and K11 (405.9 unit/mL). The $\beta$-amylase activity of the K11 strain was the highest, 34.3 unit/mL, among the isolated strains. Based on morphological, physiological properties, and API 50CHB-kit test for assimilation of 49 carbohydrates, 8 strains selected according to protease, $\alpha$-amylase, and $\beta$-amylase activities were tentatively identified as Bacillus megaterium (IA2), Bacillus subtilis (IA7, 15), Bacillus amyloliquefaciens (K8, K9, K11, and K13), and Bacillus stearothermophillus (K14). The IA7, 15, and K11 strains were finally identified as B. subtilis (99% ID) based on 16S rDNA sequencing.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.835-841
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• 2002

To reduce the salt content of Korean traditional kochujang, horseradish and mustard powder (1.2%) were added to kochujang ingredients with $4{\sim}6%$ of sodium chloride, and their physicochemical characteristics were monitored with those of the control (10% salt added) during fermentation at $25^{\circ}C$ for 120 days. The pH of kochujang gradually decreased and acidities increased at low-salt concentration. The salt lowered the acid production in proportion to the salt concentration. The amino-type nitrogen in kochujang increased during fermentation at higher proportion with lower salt concentration. Free amino acids showed the same trend as amino-type nitrogen, and their major amino acids were in order of aspartic acid, glutamic acid, and serine. Kochujang containing horseradish or mustard showed superior qualuty than the control, and 6% of salt was the acceptable level for low-salt kochujang preparation.

• Journal of Life Science
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• v.18 no.8
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• pp.1140-1146
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• 2008

In order to improve the functional properties of kochujang, garic porridge was added to traditional kochujang during manufacturing. Changes in physiochemical properties of kochujang by garic porridge addition were then investigated. No big differences in general chemical compositions was observed between three kinds of kochujangs tested in this study, general kochujang purchased from a market (GK), kochujang added with raw garlic (RGK) and kochujang added with garlic porridge (GPK). However, GPK showed higher level of antioxidant and anticancer activities than those of others. The methanolic extract of GPK showed 66.38% of DPPH radical scavenging activity, while the extracts of GK and RGK exhibited 38.44% and 50.97%, respectively. Also, the effects of three different extracts of kochujangs on cell proliferation of stomach cancer cell (MKN 45), colon cancer cell (HCT116), and lung cancer cell (NCI-H460) were investigated using MTT assay. All of three extracts exhibited the highest anti-proliferative activity against stomach cancer cell, even though the proliferation of colon cancer cell and lung cancer cell were also inhibited. Among them, the extract of GPK showed the highest anti-proliferative activity (62.35%) against stomach cancer cell. From the results obtained in the present study, we concluded that the antioxidant and anticancer activity of GPK mainly originated from garlic because GPK was consisted of 23% garlic (w/w) compared to 10% (w/w) of RGK.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.161-168
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• 1990

In order to investigate systematically characteristics of improved Kochujang in comparision with traditional Kochujang, changes of components in curing of two Kochujangs, enzyme activities of koji and Meju, and effects of salt and red pepper were measured. And it was found that the large differences of amino nitrogen and reducing sugar contents were appeared in the initial stage of the curing period, but the changes were parallel thereafter. The protease activity of koji was maximum in weak acidic pH and that of Meju was maximum in neutral pH. The optimum condition of substrate digestion was three hours at $60^{\circ}C$, and that was more effective than curing at room temperature. The activities of protease and saccharogenic amylase were decreased remarkably by adding salt and red pepper, Therefore, to decompose starch and protein effectively, the addition of salt and red pepper after substrate digestion was more favorable.

• Journal of Life Science
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• v.11 no.2
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• pp.144-152
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• 2001

In order to improve functionality of kochujang which is one of the traditional foods of Korea, sea tangle powder(2, 4, 6 and 8% sea tangle powder on the glutinous rice weight basis) was added to the raw material of kochujang and then investigated the change of physiochemical properties with control kochujang during the fermentation at 3$0^{\circ}C$ for 120 days. During 120 days fermentation, moisture and crude protein contents were gradually decreased with fermentation time, whereas crude fat content NaCl were slightly increased with fermentation time. The contents of reducing sugar of sea tangle kochujang was rapidly increased until 60 days of fermentation after that it was increased slightly up to 90 days of fermentation to the highest value and then reduced slightly or not changed approximately until 120 days. pH was reduced up to 60 days of fermentation after that it remained 4.63~4.91 in 90~120 days. Acidity was increased with fermentation time, and it was the highest value of 11.5~12.4$m\ell$ in 120 days of fermentation. Viscosity was increased with increased with fermentation time. Especially a case of additional sample of 8% sea tangle powder was highly increased until 60 days. A case of color difference value, in initial time of preparation of kochujang was distinct difference of value for additional samples respectively but as the fermentation progressed, among the samples not found consistent change of color difference value. L value was gradually decreased during fermentation. A value was decreased up to 30 days of fermentation and it was increased again totally at 60 days of fermentation. B value was decreased totally at initial time of fermentation and a case of control was increased again at 90 days of fermentation, the other samples increased again 60 days earlier than 30 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.4
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• pp.606-612
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• 1995

Three different Oyijangachi(Kochujang, Doenjang and Ganjang) have been prepared by traditional method. Cucumbers have been dipped in six different solutions for 48 hrs. After dipping, the cucumbers have been aged in Kochujang, Doenjang and Ganjang for 30 days. The acidity, pH, salt content and sensory evaluation of the cucumbers which were treated by six different solutions has measured. Moisture content of fresh cucumber was 95%, and the moisture content of Kochujang, Doenjang and Ganjang of Oyijangachi was 66.78%, 76.94% and 81.33%, respectively, after 30 days of aging. Protein content fo Kochujang, Doenjang and Ganjang of Oyijangachi increased 57%, 258% and 197%, respectively, after 30 days of aging when they compared with fresh cucumber(control). Initial acidity of Oyijangachi of cucumbers which were treated with solution 1~5 at 0 day were between 0.49 and 0.56 and increased during aging. Initial acidity of Oyijangachi treated with solution 6 was 1.84 which was low because 1% of acetic acid was added and acidity increased during aging. The pH of Kochujang, Doenjang, and Ganjang of Oyijangachi decreased 4.37, 3.98 and 4.61, respectively, after 30 days aging. Salt content of Oyijangachi dipped in various salt solutions increased as the salt content of the solution increased. Salt content of three Oyijangachi increased drastically during 0~5 days of aging and slowly increase between 5~30 days of aging. The taste and smell of Kochujang Oyijangachi were highest as treated wih 12% NaCl solution(treatment 4) and the color was highest when the Oyijangachi was treated with solution 1. The taste, smell and color of Doenjang Oyijangachi were highest as treated with 12% NaCl solution plus CaCl2(treatment 5). It was observed that the firmness of Oyijangachi was generally higher as the cucumber treated.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.463-467
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• 2005

To reduce salt content in Korean traditional kochujang, horseradish powder (1.2%, w/w) was added to kochujang with 4-10% salt, and its microbial characteristics, enzyme activities, and gas formation in kochujang were evaluated during fermentation far 120 days at $25^{\circ}C$. All treatments of kochujang had no effects on total viable bacterial numbers, which kept constant level, during fermentation (7.32-8.765 log CFU/g). Yeast numbers did not change under all treatments up to 90 days of fermentation, then decreased thereafter, ${\alpha}$-Amylase and ${\beta}$-amylase, and neutral- and acid-pretense activities of kochujang added with horseradish powder were higher than those of control group. ${\beta}$-Amylase activity of kochujang increased in proportion to salt concentration. Total accumulative volume of gas produced during fermentation of kochujang without horseradish powder was 5,892 mL/pack then decreased to 121-347mL/pack with low-salted kochujang (salt 4%, 6%) added with horseradish powder, Major gas produced was $CO_{2}(74-80%)$. Results indicate salt contents of kochujang could be lowered up to 6% by addition of horseradish powder without gas formation and quality alteration.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1570-1576
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• 1999

Quality characteristics of 3 kinds of kochujang were investigated during 6 months of fermentation in order to improve the quality of industrial kochujang to that of traditional one. Three different kinds of kochujang were prepared using Aspergillus oryzae, Aspergillus oryzae plus Bacillus licheniformis and Aspergillus oryzae, Bacillus licheniformis plus Saccharomyces rouxii. Kochujang prepared with all three microorganisms contained lesser amounts of free sugar than the other preparations and glucose was the most abundant free sugar found. Ethanol was the most abundant amount among alcohols in kochujang. Kochujang prepared with A. oryzae, B. licheniformis plus S. rouxii has more amino nitrogen content than that prepared with A. oryzae only. Capsaicin contents of kochujang decreased slightly in all three kochujang, but there was no significant differences. The results of sensory evaluation showed statistically significant difference among three samples and panel members preferred the taste and flavor of kochujang prepared with all three microorganisms to those of the other samples.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1350-1357
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• 2000

Traditional Kochujang was prepared adding horseradish or mustard powder to repress the gas formation which used to cause swelling problem during distribution. The koji for Kochujang was prepared by the strains which had high amylase and protease activities with superior flavor. The gas production from Kochujang during fermentation at $25^{\circ}C$ was ceased after stopping yeast growth completely by bactericidal components from $0.6{\sim}1.2%(w/w)$ of horseradish or mustard addition. Total viable bacterial count was not affected by adding horseradish or mustard. The amino type nitrogen content in Kochujang, which was one of the most important parameters in quality of Kochujang, increased continually during fermentation. The Kochujang fermented by P-2 isolate and added with mustard was significantly higher in amino type nitrogen content than other treatments after 120 days' fermentation. ${\alpha}-Amylase$ activity was very low while ${\beta}-amylase$ activity was high in Kochujang fermented by adding horseradish and mustard powder. The protease(acid and neutral) activities gradually increased by fermentation with no difference between treatments. The color and flavor were not different, but overall palatability of the Kochujang evaluated by sensory test showed significantly high rank in Kochujang fermented by P-2 isolate and with horseradish.

• 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.