• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.420-427
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• 1995

This study was conducted to investigate the preservative effect of low molecular weight chitosans on kimchi(2% salt concentration) during fermentation at $20^{\circ}C$. The pH and total acidity of control kimchi were lower and higher, respectively than those of kimchi samples containing chitosan. Reducing sugar content tended to be lower in control kimchi than in kimchi samples containing chitosan until 6 days of fermentation. Malic acid content was lower in control kimchi than in kimchi samples containing chitosan until 4 days of fermentation. Succinic acid content was higher in control kimchi than in kimchi samples containing chitosan at the 2 days of fermentation. Content of lactic and acetic acid also was higher in control kimchi than in kimchi samples containing chitosan at the 4 days of fermentation. The number of total microorganisms and those of microorganisms of Leuconostoc genus and Lactobacillus plantarum were higher in control kimchi than in kimchi samples containing chitosan. The number of microorganisms of Leuconostoc genus was lower in kimchi samples containing chitosan with the lower molecular weight chitosan than those with the higher molecular weight chitosan. Intensity of sensory sour taste and staled flavor were higher in control kimchi than in kimchi samples containing chitosan. There was not much difference in sensory firmness among kimchi samples, but control kimchi was evaluated slightly weaker than kimchi samples containing chitosan. Off-flavor was evaluated as weak in all the kimchi samples.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.74-81
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• 1996

Chinese cabbage Kimchi is a traditional fermented food and a numerous variety of Kimchies are produced in Korea. Most of Kimchis are produced on a small scale in the home for individual household use and recipes of Kimchis are deeply embedded in the individual cultures. Currently, however, factory-produced Kimchi is becoming popular by industrialization and changes of life style. This study was conducted to find out recipes of traditional Kimchis which are known delicious in Pusan and its environs and to develop a Kimchi with high quality. The characteristics of Kimchi recipes surveyed in Pusan and its environs are as follow: 1) Large amount of red pepper, garlic and anchovy sauce was used, which made Kimchi hot and spicy. 2) Extracts of dried anchovy or shrimp, or pear and onion juice was used to mix red pepper power. 3) Selection of good quality of Chinese cabbage and red pepper was very important step to determine quality of Kimchi. Furthermore, a numerous variety of submaterials added in Kimchi may also contribute to the high quality of Kimchi. 4) Salt concentration of Kimchi was around 2%, which was lower than it was generally known. Through this survey, it was suggested that maintaining low salt content of Chinese cabbage during salting make Kimchi crispy and juicy.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.534-541
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• 2018

Kimchi (a traditional Korean fermented vegetable) was prepared with a starter, Lactobacillus zymae GU240 producing ${\gamma}$-aminobutyric acid (GABA), and one precursor of GABA (glutamic acid, glutamic acid monosodium salt (MSG), or kelp extract). L. zymae GU240, an isolate from kimchi, can grow at 7% NaCl and low temperature. Five different kimchi samples were fermented for 20 weeks at $-1^{\circ}C$. Kimchi with starter alone could not produce GABA. The GABA content was highest in kimchi with co-inoculation of the starter and MSG (1% (w/w)). Kimchi co-inoculated with the starter and kelp extract powder (3% (w/w)) had the second highest GABA content. Addition of glutamic acid powder (1% (w/w)) caused a reduction in the pH level of kimchi and growth inhibition of lactic acid bacteria and yeasts. Kimchi samples with MSG or kelp extract showed improvement of sensory evaluation scores. The results demonstrate the possibility to produce kimchi with improved functionality and taste by using L. zymae GU240 as a starter along with a suitable precursor such as MSG or kelp extract.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.219-227
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• 2015

This study was designed to investigate dietary life related to sodium of participants in hypertension and diabetes preventive education at the public health center located in Incheon Metropolitan City. Subjects were comprised of 301 adults (males: 102, female: 199) of age 50 years and above. The questionnaire for dietary life and salty taste assessment were performed on the subjects. Data were analyzed using SPSS package (ver. 18.0). According to the result of questionnaire for dietary behavior, 70% of the subjects were in the low salt intake group (p<0.001). In the result of questionnaire for dietary frequency, all ages groups were in the low salt intake group (p<0.01). The data of questionnaire for dietary behavior showed that the subjects of age above 75 years preferred salted seafood, soup, and kimchi (p<0.01). The data of questionnaire for dietary frequency showed that the subjects of age between 65 and 74, least chose fried kimchi, noodle, and soybean paste soup with clams (p<0.05), and the healthy adult groups chose kimchi stew, ssam and ssamjang (p<0.05). The score for dietary behavior in male subjects was higher than female subjects (p<0.01). In particular, the score for dietary frequency was the lowest in the subjects of age between 65 and 74 (p<0.01). The mean value of salty taste assessment in the subjects was 0.41% which is higher than the ideal value of 0.3% (p<0.01). Offering more nutrition education and continuous feedback of healthcare center may be needed to improve the health status of the adults.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.257-262
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• 2011

The objective of this study was to investigate the changes in the microbial properties of taurine supplemented Kimchi during fermentation at $6^{\circ}C$ for 46 days. Chinese cabbage was brined in 10% salt solution for the control Kimchi and in 10% salt solution containing 1, 2 or 4% taurine (w/w, based on cabbage) for taurine supplemented Kimchi (Taurine I, II, and III groups, respectively). The pH values of all the groups dramatically decreased after 1-day of fermentation. Total numbers of viable cells were highest at 5-days of fermentation for the control, at 9-days of fermentation for Taurine I, and at 23-days of fermentation for Taurine II and III. The highest numbers of lactic acid bacteria were found at 9-days of fermentation for the control and Taurine I, and at 18-days of fermentation for Taurine II, and at 13-days of fermentation for Taurine III. The fermentation periods required to reach the highest numbers of Leuconostoc bacteria for Taurine I, II and III were longer than that for the control, suggesting that taurine might inhibit the growth of Leuconostoc bacteria during Kimchi fermentation. Based on the results obtained from the present study, it is concluded that adding taurine to the production of Kimchi could delay the ripening period of Kimchi.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.335-342
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• 2015

We conducted a study on mukeun (long-term fermented) kimchi ripened over one year in an attempt to develop an alternative salt and improve the quality of low-salt kimchi. However, few studies have focused on mukeun kimchi that has been fermented for a short time in different salinity conditions. Therefore, the aim of this study was to investigate the physicochemical characteristics that occur during the fermentation of mukeun kimchi samples produced with different conditions of salinity and fermentation temperature. Kimchi samples were produced at 3 different salinity levels: 1.6%, 2.4%, and 3.2%. Previous studies revealed that the optimum fermentation time at pH 4.1 was 128 hours at $18^{\circ}C$ and 417 hours at $12^{\circ}C$; furthermore, the samples were stored for 12 weeks under the condition of $-1^{\circ}C$ after fermentation. Total cell increased on week 0 of storage and decreased according to the storage period. Total cell was the highest at 3.2% salinity and had a high value at $18^{\circ}C$ temperature during the storage period. Based on the physiochemical results, mukeun kimchi at a salinity of 3.2% can be fermented for a short time, and low-salt kimchi at a salinity of 1.6% and fermented at $18^{\circ}C$, is similar to mukeun kimchi at 2.4% salinity.

• Journal of the Korean Society of Food Culture
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• v.37 no.1
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• pp.61-72
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• 2022

This study investigated the minimum salt concentration required for achieving the optimal quality characteristics of sauerkrauts made by adding 0.5, 1.0, 1.5, 2.0, and 2.5% (w/w) of sea salt to cabbage according to the fermentation period. For evaluating the quality characteristics, we measured the microorganisms (lactic acid bacteria, yeast, and coliform group), pH, total acidity, salinity, chromaticity, and hardness every 24 hours. The lactic acid bacteria were identified and analyzed, and acceptance test was carried out on the 4^th day of fermentation. The results showed that the salinity of 0.5, 1.0, 1.5, and 2.0% sauerkrauts on the 4^th day of fermentation was lower than the average salinity of Baechu-Kimchi. The 0.5, 1.0, 1.5, and 2.0% sauerkrauts had significantly higher lactic acid bacteria than the 2.5% sample, and the coliform group was not detected after the 5^th day of fermentation. Among the microbes identified, Weissella cibaria JCM 12495 was found only in domestic sauerkraut, in addition to Lactococcus lactis NCDO 604, Leuconostoc citreum JCM 9698, and Lactobacillus sakei DSM 20017. The results of the acceptance test show that 1.0 and 1.5% sea salt sauerkraut had significantly higher overall acceptance compared to the other samples. In conclusion, sauerkraut with a salt concentration of 1.0 and 1.5% (w/w) had abundant lactic acid bacteria and excellent sensory properties, suggesting that the production of low-salted sauerkraut can be adopted to reduce consumer salt intake in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.429-437
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• 1999

A mathematical model was established for estimating changes in pressure and volume of permeable kimchi packages. The model comprises the CO2 gas production from kimchi and permeation of O2, CO2 and N2 through the permeable film or sheet. Using the developed model, the effects of various packaging variables on the pressure and volume changes were analyzed for rigid and flexible packag es of kimchi(3% salt content) at 15oC, and then effect of storage temperature was also looked into. In case of rigid pack of 400g, using the plastic sheet of high CO2 permeability and initial vacuumizing can help to relieve the problem of pressure build up. The lower fill weight can further reduce the pressure, but will result in higher packaging cost. For the flexible package of 3 kg, highly permeable films such as low density polyethylene(LDPE) and polypropylene can reduce the volume expansion. Higher ratio of CO2 permeability to O2 and N2 permeabilities are effective in reducing the volume expansion. Increased surface area cannot contribute to reduction of volume expansion for highly permeable flexible packages of kimchi. For the impermeable packages, pressure and volume at over ripening stage (acidity 1.0%) increase with decreased temperature, while those at optimum ripening stage(acidity 0.6%) change little with temperature. Pressure of permeable rigid LDPE package increases with tem perature at any ripening stage, and temperature affects the volume of flexible LDPE package very slightly. Experimental verification of the present results and package design with economical consid eration are needed as a next step for practical application.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1021-1027
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• 1997

$CO_2$production in fermentation of dongchimi was measured and interrelated with changes in pH and titratable acidity. The effects of salt content and temperature on $CO_2$production rate were analysed. Fermentation of dongchimi showed drastic pH decrease in early stage and subsequent levelling off around 3.9, with linearly increased acidity up to 0.3~0.4% optimum quality. $CO_2$production of dongchimi could be analysed to consist of two consecutive stages of constant rate. The first stage $CO_2$production of higher rate moved to the second stage of lower rate when acidity rose beyond 0.3%. When compared to those of 1 and 2% salt content, dongchimi of 3% salt showed lower $CO_2$production rate in the 1st stage and slower acidity change through the whole fermentation period. However, it resulted in the product of highest $CO_2$accumulation at optimal ripeness because of consistent $CO_2$production of longer 1st stage period and relatively high $CO_2$production rate in 2nd stage. $CO_2$production depended on temperature less compared to acidity change(activation energy: 57.3 and 44.3kJ/mol for $CO_2$production of 1st and 2nd stages, respectively; 79.3kJ/mol for acidity change), which means higher ratio of $CO_2$production rate relative to acidity increase at lower temperature. Slower increase in acidity at low temperature also was shown to extend the period of 1st stage $CO_2$production. Therefore, low temperature fermentation was effective in producing the high $CO_2$content dongchimi at adequate acidity, which is desirable organoleptically.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.415-420
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• 2010

In Korea, oysters are used as an ingredient of Kimchi (Korean pickled cabbage) in early winter. Although viral contamination of oysters, including contamination by norovirus, can provoke gastroenteric illness, little is known of the epidemiological relationship to outbreaks. We postulated that Kimchi ripening can reduce the infectivity of norovirus, in order to test this hypothesis, we carried out a model experiment. Since norovirus is currently regarded as non-culturable, feline calicivirus (FCV) was used as a surrogate to examine the activation of norovirus with Kimchi ripening. In commercial well-prepared Kimchi, the infectivity ($TCID_{50}$) of FCV decreased by 2 log every 12 hours and reached the limit of detection after 48 hours during over-aging at $25^{\circ}C$. During storage at $4^{\circ}C$, the infectivity ($TCID_{50}$) of FCV decreased slowly and reached 5.00 $TCID_{50}$ after 48 hours. The low pH appears to affect the infectivity of FCV directly via organic acids produced by ripening during over-aging and storage. In neutralized lab-prepared Kimchi (pH 7.0), the infectivity ($TCID_{50}$) of FCV also decreased and reached the limit of detection after 72 hours at $4^{\circ}C$. This indicates that there are substances beside organic acids in Kimchi that originate from the raw materials and are produced during ripening. Among the raw materials, salt-fermented anchovies and garlic showed high direct antiviral activity. The main factor decreasing the infectivity of FCV in Kimchi was the high acidity caused by organic acids, regardless of the type, produced by ripening. Furthermore, unknown secondary products of microorganisms associated with Kimchi ripening and antiviral materials originating from raw material might contribute to the decreased infectivity of FCV, the surrogate of norovirus.