• 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.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1166-1174
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• 1997

This study was designed to investigate the changes in physicochemical and sensory characteristics of traditional kochujang during aging, which was prepared with a different meju fermented for various periods of time. The non-volatile organic acid contents in all samples gradually increased up to 90 days of fermentation. Kochujang prepared with a 40-day-fermented meju had $1.14{\sim}2.54$ times highter organic acid content after 90 days of aging as compared to other kochujang preparations. The most abundant free sugars were found to be glucose and fructose representing $82.27{\sim}100%$ of total free sugar contents in kochujang. 17 kinds of free amino acid including Glu, Asp and Met were found in traditional kochujang aged for 90 days. Glu was noted as the most contributing amino acid to the brothy taste of kochujang in the light of increasing ratio and content of Glu among free amino acids during aging. The total free amino acid contents of kochujang increased with an Increase in fermentation time of meju. Results of sensory evaluation revealed that kochujang prepared with a 40-day-fermented meju was best in terms of flavor and taste. These results suggest that kochujang prepared with a 40-day-fermented meju had the highest quality in terms of physicochemical and sensory characteristics of kochujang.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1091-1097
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• 2002

In order to improve palatability and quality of traditional kochujang, kiwifruit (Actinidia deliciosa) was added to traditional kochujang fermented for 3 months. Physicochemical and microbial characteristics were investigated during fermentation at $30^{\circ}C$. Moisture contents of all treated kochujangs increased with increasing amount of kiwifruit added during fermentation. pH of kiwifruit-added kochujang was lower than that of the control kochujang, whereas no significant differences in titratible acidity was observed among all treatments. Crude protein and salt contents of kiwifruit-added kochujang were lower than those of the control, whereas no difference in crude fat contents were found. Ethanol and amino-nitrogen contents of 6 and 9% kiwifruit-added kochujang were higher than those of the control. Fructose contents of kiwi-added kochujangs were higher than that of the control. Major organic acids of kochujang were in the order of malic acid > citric acid > succinic acid > acetic acid > lactic acid > oxalic acid. Succinic acid level increased significantly during fermentation and was higher in kiwifruit-added kochujang than in the control. Bacterial cell counts of all treatments were not different, and viable cell count of yeast was slightly higher in kiwifruit-added kochujang only at the initial fermentation period. Sensory evaluation revealed that the addition of 9% kiwifruit was the optimum condition for improving kochujang quality.

• 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.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.193-200
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• 1997

In order to manufacture the low salt and functional Kochujang, salt amount was reduced to 6% and chitosan was added to 0.25% to the Kochujang preparation. The contents of ash, moisture, crude fat and crude protein in Kochujang were not affected by the reduced salt concentration and chitosan addition. pH and titratable acidity were not significantly changed by the addition of chitosan. Ethanol content was higher in 6% salt Kochujang tan in 9% salt Kochujang and decreased by the addition of chitosan. Reducing sugar content was lower in 6% salt Kochujang than in 9% salt Kochujang and increased by chitosan addition. $\alpha$-Amylase activity was slightly inhibited by the addition of chitosan, however, $\beta$-amylase, acidic protease and neutral protease activities were not affected. Amino nitrogen and ammonia nitrogen contents were higher in 6% salt Kochujang than in 9% salt Kochujang, but ammonia nitrogen production was significantly decreased by chitosan addition. Also the growth of bacteria and yeasts were slightly inhibited by the addition of chitosan. From the above results we concluded that 0.25% chitosan was the good concentration to prepare the low salt and functional Kochujang.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1174-1181
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• 2003

A part of Aspergillus oryzae koji was replaced with Bacillus sp. koji to improve the quality of kochujang, and the resulting effects on enzyme activities, microbial characteristics, and physicochemical properties were investigated during fermentation. The activity of amylase was higher in the kochujang prepared with Asp. oryzae koji. The activity of protease increased as the ratio of Bacillus. sp. koji increased. Viable cell counts of yeast and bacteria of the kochujang increased with increasing ratio of Bacillus sp. koji. The Hunter a-values of the Bacillus sp. koji kochujang were higher, and the degree of increase in the total color difference $({\Delta}\;E)$ was lower in the Bacillus sp. koji group. Consistency and water activity of the kochujang prepared with Bacillus sp. koji was higher, and the pH and titratable acidity of the kochujang also changed slightly. As the ratio of Asp. oryzae koji increased, sugar content decreased. However, the ethanol content of the kochujang did not significantly change. Amino nitrogen content of the kochujang increased, while ammonia nitrogen content decreased as the ratio of Bacillus sp. koji increased. After 12 weeks of fermentation, the result of sensory evaluation showed that C kochujang (75% of Asp. oryzae koji replaced by Bacillus sp.) was more acceptable (p<0.05) than the other groups in taste, color, flavor, and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.256-263
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• 2001

Physicochemical characteristics of kochujang prepared with meju, koji and mixture of meju and koji were analyzed during fermentation in order to improve quality of traditional sikhe kochujang. Amino nitrogen content, an index of kochujang quality, was remarkably higher in kochujang prepared with p-2 koji, p-1 koji, mixture of p-2 koji and meju. Titratible acidity of kochujang slightly increased and pH of kochujang increased until 40 days of fermentation and then decreased there after. Citric acid was found as a major organic acid followed in decreasing order by malic, oxalic, succinic, acetic and lactic acids. As a free sugar, maltose, glucose and fructose were detected. Free sugar content was higher in kochujang prepared with p-1 koji than the others. The major free amino acids were aspartic acid, glutamic acid, alanine, phenylalanine and arginine, and total free amino acid content was higher in kochujang prepared with koji, and mixture of meju and koji than the one with traditional meju only. In sensory evaluation, all tested groups did not show a significant difference. This result indicates that addition of koji to sikhe kochujang influences on taste components like free sugars and free amino acids, but decisively not on the sensory properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1292-1299
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• 2011

This research aimed to determine the quality characteristics of kochujang made of sword bean chunggukjang. The effects of chunggukjang addition were compared in products fermented for 90 days. During the fermentation period of kochujang, sword bean chunggukjang was added at 0, 2, 5, 8, and 10%. The moisture content ranged from 40.24 to 42.83% (w/w). After 90 days of fermentation, sodium chloride was at around 10.2 to 10.3%, which was not much different from that of control kochujang (SBC 0) before and after fermentation. The color values were not significantly different between SBC kochujang and traditional kochujang. The microbial counts in 0, 2, 5, 8, and 10% SBC kochujang fermented for 90 days were around $5.42{\times}10^7$ to $9.59{\times}10^7$ CFU/g for aerobic viable cells, $1.14{\times}10^2$ to $9.73{\times}10^2$ CFU/g for yeast, and $8.49{\times}10^2$ to $1.25{\times}10^3$ CFU/g for Bacillus cereus. Sensory evaluation of kochujang showed that the comprehensive preference was 5.40, 5.15, 6.30, 6.10, and 6.95, respectively, for SBC 0, 2, 5, 8, and 10%. In conclusion, the quality difference between SBC and traditional kochujang was not significant, and sensory evaluation of kochujang showed that SBC 10% received the highest score.

• 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.