• Applied Biological Chemistry
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• v.33 no.3
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• pp.257-260
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• 1990

The weight increasing rate of soda lime, absorbing carbon $dioxide(CO_2)$ generated during fermentation at $25^{\circ}C$, was measured In investigate the maturity of Kimchi at every 6 hours. The increasing rate was maximum at 36hours It was compatible with pH, titrable acidity and sensory evaluation test in optimum curing time. So, this method is thought as useful one for the measurement of the maturity of Kimchi.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.413-422
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• 2013

This study investigates the kimchi from Jangsu area (JSK) and its comparison with commercial kimchi (CMK). We conducted a sensory evaluation for the pH, titratable acidity, salinity, hunter's color values and mechanical characteristics of kimchi. The pH of JSK is significantly higher than CMK throughout the fermentation (p<0.001). At 15 days, JSK reached the stage of optimal maturity for pH 4.23~4.55 and CMK showed pH 3.96~4.00 as conditions after the optimal maturity (p<0.001). From the results of acidity analyses, CMK also showed higher acidity values than JSK (p<0.001), indicating that the rate of fermentation progress was faster in CMK. Salinity of JSK was a litter higher than CMK1 and CMK2 (p<0.001) and JSK indicated significantly higher L, a, b values during fermentation (p<0.001). Moreover, the textural values were significantly higher in JSK2 and JSK3 retaining hardness of the tissues. In the sensory assessment, the color, flavor, crispness, taste, and overall preferences were higher in JSK3 at 15 days and 30 days than CMK. Therefore, it seems necessary for recipe developments of kimchi with local characteristics in order to industrialize kimchi by using alpine crops at Jangsu area.

• Korean Journal of Food Science and Technology
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• v.19 no.3
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• pp.250-256
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• 1987

An attempt was made to establish a simple and rapid method for the evaluation of Kimchi quality. Four kinds of Kimchi included one home made traditional Kimchi were stored at $4^{\circ}C$ and$25^{\circ}C$ and biochemical changes, including pH, total acidity, volatile acidity, volatile basic nitrogen, vitamin C, NaCl, glucose, nitrite and resazurin value were determined and tested for the relationship with sensory evaluation. The change in pH, total acidity and resazurin value were highly correlated with the sensory maturity of Kimchi-Resazurin value was strongly influenced by the sample dilution and fermentation temperatures. It was concluded that resazurin test with sample solution of $2{\sim}4%$ could be used as a rapid method for the estimation of the maturity of Kimchi.

• Journal of the Korean Home Economics Association
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• v.26 no.1
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• pp.51-59
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• 1988

In the present study, an attempt was made to observe the effect of calcium-sources and preservatives on Kimchi fermentation. After pre-fermentation at room temperature for 16 hours, each Kimchi was stored at 4$^{\circ}C$. Changes of vitamin contents(vitamin C, thiamin, riboflavin and $\beta$-carotene) during the fermentation of Kimchi were determined. It was also attempt to relate the fermentation of Kimchi with the changes in chemical and organoleptic characteristics, such as pH, total acidity and reducing sugar. The findings were summarized as follows; 1. During Kimchi fermentation, the pH decreased steady and total acidity increased slowly in the follow order: K-Sorbate+acetic acid, k-Sorbate, Ca-Lactate and Control. the lower of pH and the higher of total acidity, the less of reducing sugar was remained. 2. changes of total vitamin C and reduced ascorbic acid contents during the Kimchi fermentation did not differ significantly from each other. At the begining of fermentation, Kimchi samples contained 20~25mg/100g of total vitamin C and 5~14 mg/100g of reduced ascorbic acid. In the final stage, however, 15~19 mg/100g of total vitamin C and 1~3 mg/100g of reduced ascorbic acid were remained. 3. The contents of thiam in and riboflavin were 30 to 42 meg/100g and 50 to 67 meg/100g at the initial stage, respectively. They increased with the degree of maturity (approximately 2 times of the content of the initial stage) and then gradually decreased. The content of $\beta$-carotene was found to be decreased with the degree of maturity. 4. The results of sensory evaluation indicated that Kimchi added with Ca-Carbonate, Ca-Carbonate+acetic acid and Ca-lactate were better than Control.

• Korean journal of food and cookery science
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• v.11 no.1
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• pp.37-43
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• 1995

Effect of the pretreatment with acetic acid(0.01%, 0.05%, 0.1%) on the fermentation of Chinese cabbage Kimchi, and differences in the degree of maturity between Chinese cabbage blades and midribs were observed. To estimate the degree of maturity, correlation analysis was used with several variables such as pH, titratable acidity, volatile acidity, ascorbic acid content, resazurin test value and pH/acidity ratio. Based on the pH and titratable acidity, the degree of maturity of Chinese cabbage midribs fermented at 10$^{\circ}C$ until the optimum stage of fermentation increased more rapidly than those of the blades. The stage of maturity of Kimchi pretreated with 0.01% acetic acid were slightly prolonged, compared to those pretreated with acetic acid at the higher levels. The pH of Chinese cabbage midribs and blades pretreated with acetic acid was lower than those of control between 2nd and l0th day of fermentation. The volatile acidity of Chinese cabbage midribs and blades increased proportionally with the concentration of acetic acid. The ascorbic acid contents of Chinese cabbage midribs showed higher than those of Chinese cabbage blades. During the fermentation, the higher concentration of acetic acid was used, the less ascorbic acid content was remained. The pH/acidity ratio, volatile acidity, ascorbic acid content and resazurin test value of Chinese cabbage midribs and blades during Kimchi fermentation at 10$^{\circ}C$ showed good correlations with the pH and titratable acidity.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.421-426
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• 2007

This study was carried out to investigate the properties of Kimchi made with potato as compared to Kimchi made with radish. The pH, acidity, hardness, and number of lactic acid bacteria were examined as properties of the Kimchi to determine the suitability of adding the potato and with focus on the possible duration of storage. First in the case of pH, the storage duration at pH $4.2{\sim}4.3$, which is the state for optimal tasting Kimchi, was approximately 10days in the control group, while that of the experimental group was 10 to 16 days, and thus, longer than the control. Second in the case of acidity, representing the maturity of Kimchi, we examined the time it took to reach 0.6% acidity, in which the experimental group took more longer time than the control. Although the experimental group was slower to mature than the control, the period for keeping at the proper pH was longer than that of the control group. Thirdly, in the case of hardness, which relates to softening, the experimental group had remarkably high values. This suggests that the Kimchi in the experimental group had a more rigid texture and more difficultly softening than the control group. Lastly in the case of the number of lactic acid bacteria, which closely relates to the process of fermentation, there were no significant differences. In conclusion, these results indicate that adding potato to Kimchi can extend its storage period.

• The Korean Journal of Food And Nutrition
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• v.30 no.5
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• pp.935-942
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• 2017

In the present study, kohlrabi-kimchi was prepared for assessment of changes in sensory qualities and measurement of changes in quality characteristics according to the storage period for the purpose of using kohlrabi as an ingredient of Kimchi. Examination of the physicochemical properties of kohlrabi-kimchi according to the storage period showed that the acidity increased steadily throughout the storage period, while soluble-solids content, pH and hardness decreased as the storage period elapsed. Meanwhile, the L value increased and then it decreased as the storage period elapsed, but, the a value increased and the b value gradually decreased after day 14 of storage. Reducing sugars increased up to day 10 of storage, and then they decreased slowly after day 15 of storage. Measurement of changes in lactic acid bacteria in kohlrabi-kimchi according to the storage period showed bacterial growth showing typical tendencies of Kimchi with a rapid increase on day 5 of storage and a decrease thereafter. Assessment of sensory qualities of kohlrabi-kimchi according to the storage period showed that the highest scores for appearance and sourness, odor, texture, and overall scores were obtained on day 15 of storage. Based on the above results, it was determined that the optimal maturity period of kohlrabi-kimchi is day 15 of storage.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.26-32
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• 1990

Attempts were made to define the characteristics of microbial community as an indicator of Kimchi fermentation. Determination of communities was carried out by simple Gram-stain, followed by direct microcopic counts. In room-temperature $(15^{\circ}C)$ fermentation, microbial succession was occurred in the order of communities of Gram-positive bacteria, yeasts and Gram-negative bacteria. It was characteristic that Gram-positive bacterial community was developed during the production of lactic acid, yeasts community was developed to cause rancidity, and Gram-negative bacterial community was relevant to maceration (or softening) as well as rancidity. The fluctuation of apparent Gram-negative reaction group might be used as a criterion of death or aging of Gram-positive bacterial populations. In low-temperature fermentation $(5^{\circ}C)$, however, it was found that yeasts and Gram-negative bacterial communities did not developed but only Gram-positive bacterial community did. It follows from these results mentioned above that maturity of Kimchi depends on the development of Cram-positive bacterial community. Thus, the size and occurrence of microbial community are avaiable for an indicator of Kimchi fermentation, and also determination of community could be a useful method to predict the maturity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.298-306
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• 2016

Planting date shift is one of the means of adapting to climate change in Kimchi Cabbage growers in major production areas in Korea. This study suggests a method to estimate the potential yield of Kimchi Cabbage based on daily temperature accumulation during the growth period from planting to maturity which is determined by a plant phenology model tuned to Kimchi Cabbage. The phenology model converts any changes in the thermal condition caused by the planting date shift into the heat unit accumulation during the growth period, which can be calculated from daily temperatures. The physiological maturity is estimated by applying this model to a variable development rate function depending either on growth or heading stage. The cabbage yield prediction model (Ahn et al., 2014) calculates the potential yield of summer cabbage by accumulating daily heat units for the growth period. We combined these two models and applied to the 1km resolution climate scenario (2000-2100) based on RCP8.5 for South Korea. Potential yields in the current normal year (2001-2010) and the future normal year (2011-2040, 2041-2070, and 2071-2100) were estimated for each grid cell with the planting dates of July 1, August 1, September 1, and October 1. Based on the results, we divided the whole South Korea into 810 watersheds, and devised a three - dimensional evaluation chart of the time - space - yield that enables the user to easily find the optimal planting date for a given watershed. This method is expected to be useful not only for exploring future new cultivation sites but also for developing cropping systems capable of adaptation to climate change without changing varieties in existing production areas.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.125-130
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• 1994

This study was intended to observe the effect of the addition of soused shrimp(5%, 10%) and/or cooked glutinous rice flour(2.5%) on the changes of low molecular nitrogen compounds content of Kimchi during fermentation at $10^{\circ}C$ for 14 days. The pH, total acidity, free sugar, nitrite, dimethylamine(DMA) and volatile basic nitrogen(VBN) contents were measured. The nitrite contents were approximately 0.16 to 1.31 mg/Kg at the inital stage of fermentation. It was found that the nitrite contents of Kimchi samples with 10% soused shrimp$(S_2,\;GS_2)$ were relatively high among the Kimchi samples. However, nitrite was not detected after the stage of optimum maturity in all Kimchi samples. The dimethylamine(DMA) content of Kimchi samples were increased during the fermentation with increasing the soused shrimp concentration. Cooked glutinous rice flour enhanced the DMA production of Kimchi with soused shrimp. DMA content were 0.93-1.2 mg/kg at initial stage end 1.6-2.26 mg/kg at final stage of fermentation of the Kimchi with soused shrimp. As the fermentation period increased, the VBN contents of Kimchi samples with soused shrimp$(S_1,\;S_2,\;GS_1,\;GS_2)$ were apparently higher than those of Kimchi samples without it(C, G). Though the soused shrimp enhanced the volatile basic nitrogen production but cooked glutinous rice did not affected VBN production during Kimchi fermentation.