• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.333-339
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• 1997

The effects of kind of vegetables and of the kind and amounts of fermented fish sauce on the formation of nitrosamine (NA) during kimchi fermentation were investigated. Kimchies made of Chinese cabbage, cucumber, and radish with fermented shrimp, anchovy and liquid sauces were fermented at 4$^{\circ}C$ for 6 weeks and the changes in the content of nitrate, nitrite, trimethylamine (TMA), dimethylamine (DMA) and NA were studied. Nitrate content in kimchies made of Chinese cabbage, cucumber, and radish increased at the initial period of fermentation, but it decreased at the later period. Nitrite was not detected at the later period of kimchi fermentation. Overall, there have not been great changes in the contents of nitrite and nitrate. However, there have been considrable changes in the contents of TMA and DMA as fermentation progressed. Only nitrosodimethylamine (NDMA) at the level of 0.5~10.3 $\mu\textrm{g}$/kg was formed in three kinds of kimchies. More NDMA was formed in radish and cucumber kimchies than in Chinese cabbage kimchi. The pH was lowered faster in radish and cucumber kimchies than in Chinese cabbage kimchi. More NDMA was formed in Chinese cabbage kimchi made with fermented shrimp sauce than those with anchovy or liquid sauces. Shrimp sauce contained higher amount of DAM than anchovy and liquid sauces. The contents of NDMA tended to increase as the amount of shrimp sauce increased. The kind and amount of fermented fish sauce used for kimchi preparation may be an important factor affecting the formation of NDMA.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.263-266
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• 1999

Pectic substances are important to sustain the textural properties of kimchi during fermentation and distribution. Therefore proper control of pectin degrading enzyme activity is critical on quality control in kimchi industry. Pectin degrading enzymes of kimchi ingredients were assayed to improve the product quality. Among pectin degrading enzymes, polygalacturonase and pectinesterase were selected. The specific activity of polygalacturonase was the highest in salted and fermented anchovy, followed by chinese radish. Considering the amount of protein contents, salted and fermented anchovy and dried red pepper showed higher polygalacturonase activity than other ingredients. In terms of specific activity, chinese radish showed the highest pectinesterase activity, followed by salted and fermented anchovy. However, the total activity of salted and fermented anchovy was the highest. Chinese radish showed higher pectinesterase activity than any other ingredients.

• Journal of the Korean Society of Food Culture
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• v.25 no.4
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• pp.428-455
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• 2010

Radish kimchi is a typical side-dish in Korean traditional food and is a way of keeping vegetables for a extended period using fermentation. This study examined the classification, usage, eating history, variety, and recipes of Korean radish kimchi through ancient and modern era literature. The Korean radish kimchi were categorized into six groups: kkakttugi, seokbakji (or nabakkimchi), dongchimi, jjanji, jangachi, and jangkwa. According to the record, the eating history of radish kimchi comes from before the age of the Three Kingdom period. Radish was preserved in salt, vinegar, soybean paste or lees of fermented liquor in the early times. This pickled radish was not supposed to be watery. Radish kimchi was divided into watery kimchi (dongchimi) during the period of United Silla and the Koryo Dynasty. Kimchi was mixed with Chinese cabbage to make seokbakji or nabakkimchi. Up to the early Chosun Dynasty, the key ingredient of kimchi was radish. After the middle of the Chosun Dynasty, kimchi was mixed with red pepper powder, salted fish, soybean sauce, and various ingredients. There were many kinds of radish kimchi during the late Chosun Dynasty. In the 11 Korean recipe books published within the past 100 years, there are nine kinds of kkakttugi, three kinds of seokbakji, four kinds of dongchimi, three kinds of jjanji, nine kinds of jangachi, and five kinds of jangkwa. Kkakttugi (cubed, sliced or julienne radish) was pickled with salt, red pepper powder, garlic, green onion, oyster, sugar, salted fish, and more. Seokbakji and nabakkimchi were not as salty, so they could not be preserved as long. Dongchimi (watery radish kimchi without red pepper powder) was made of radish, water, salt, 18 side ingredients, 13 condiments, and seven garnishes. Jjanji was pickled to be very salty and was eaten during summer. Jangachi can be used as a regular side dish and is made of radish or dried radish slices pickled or seasoned with salt, soy sauce, vinegar, soybean paste, lees of fermented liquor, and spices. Jangkwa is used as a stir-fry method and has been segregated from jangachi relatively recently.

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2004.11a
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• pp.150-157
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• 2004

Cruciferous vegetables are rich in organosulfur compounds such as isothiocyanates and sulfides. While the isothiocyanates, corresponding to pungent principle, are generated from myrosinase-catalyzed hydrolysis of glucosinolates, the sulfides can be generated non-enzymatically. Recent studies provide evidences that some sulfur compounds in these vegetables show a chemopreventive action against carcinogenesis; while isothiocyanates such as sulforaphane induce phase 2 enzymes (glutathione S-transferase/quinone reductase), disulfides tends to elevate the level of phase 1 and 2 enzymes. Especially, sulforaphane rich in Cruciferae vegetables has been reported to express anticarcinogenic effect in some organs such as liver, kidney or intestine. When the level of sulfur compounds in Cruciferous and Alliaceous vegetables was determined by GC/MS (SIM), the richest in sulforaphane is broccoli followed by turnip, cabbage, radish, kale, cauliflower and Chinese cabbage. Meanwhile, the sulfides are predominant in Alliaceous vegetables such as onion. In related study, the administration of vegetable extract elevated the GST level by 1.5 fold for broccoli, 1.4 fold for radish, and 1.3 for onion. Thus, the vegetables frequently used in Korean dish contain relatively high amount of anticarcinogenic sulfur compounds. Moreover, the combination of broccoli and radish extracts elevated the GST induction up to 1.84 folds of control. In addition, the Kakdugi, fermented radish Kimchi was observed to show a comparable GST induction despite the decomposition of methylthio-3-butenylisothiocyanate (MTBI). Therefore, the combination of vegetables including broccoli, and fermented radish Kimchi would be useful as a functional food for chemoprevention.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.262-266
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• 1991

The physicochemical properties of dongchimi, a Korean fermented Chinese radish, were investigated for their changes during fermentation in 7% NaCl brining solution at $4{\sim}35^{\circ}C$, The results showed that the relative viscosity of brining solution were initially decreased before steady increase there after. The Hunter L value increased and a value decreased and the turbidity also showed a similar increase as L value as affected more significantly by high fermentation temperature. The hardness of Chinese radish decreased initially followed by a little increase and then slowly decreased at later stage of fermentation. A linear relationship was found with decrease in salt concentration in brining solution and logarithmic value of brining time and activation energy was calculated for temperature range of $4{\sim}35^{\circ}C$ from the relationship.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.213-218
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• 1991

Addition of salts or their mixtures and microwave heating were studies for their effects on Kakdugi fermentation. The Kakdugi, a Korean fermented Chinese radish, were prepared by salting in 15% NaCl solution and fermented at $25^{\circ}C$. From the results, a first order reaction relationship was found between salt permeated into the radish and time during brining in $5{\sim}10%$ NaCl solution. Addition of 0.05M KCl into 15% NaCl brining solution or microwave heating of salted radish for 3 minutes showed a little decreasing effect on Kakdugi fermentation rate while beating for 1 or 2 minuted resulted a rather increase. When three different salt mixtures in the concentration range of $0.001{\sim}0.01\;M$ were added into half fermented Kakdugi(appr. pH 4.4), the fermentation was greatly controlled based on pH change. Among the salt mixtures, mixture III$(Na_2HPO_4,\;Na_2PO_4,\;NaNO_2,\;Ca\;EDTA,\;Sod.\;citrate)$ showed a most significant effect where the time required to reach pH 4.0 after addition was extended by more than 6 folds when it was compared to the control method.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1333-1338
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• 1998

Several enzymes of kimchi ingredients were assayed to improve the product quality using these quality related enzyme information. Among various hydrolases, amylase and protease were selected with respect to lactic acid fermentation. Peroxidase and ascorbic acid oxidase were studied for off flavor production and ascorbic acid destruction. The amount of protein in kimchi ingredients, specific and total enzyme activity of sample were compared. Regarding total enzyme activity of sample, ${\alpha}-amylase$ activity of salted and fermented anchovy, dried red pepper and salted and fermented shrimp were higher than other ingredients. Activity of salted and fermented anchovy was 2,790.0 units/g sample. Salted and fermented anchovy, oyster and Chinese radish showed the highest ${\beta}-amylase$ activity (4.4, 2.1, 1.0 units/g sample, respectively). Salted and fermented anchovy showed the highest protease activity of 13.4 PU/g sample, followed by salted and fermented shrimp and dried red pepper. For peroxidase, Chinese radish, cucumber, green onion showed the highest activity of 7.2, 6.8 and 5.6 units/g sample, respectively. In case of ascorbic acid oxidase, salted and fermented anchovy showed the strongest enzyme activity (331.4 units/g sample), followed by dried red pepper and salted and fermented shrimp.

• Korean journal of food and cookery science
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• v.16 no.1
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• pp.57-64
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• 2000

An optional ingredient, Gatt(Brassica juncea) was adopted to improve the quality of Dongchimi during fermentation. The final weight percentage of Gatt in Dongchimi was adjusted to 0, 3, 5, 10, or 15%, per radish. Sensory and microbiological characteristics were determined during fermentation at 10$^{\circ}C$ for 45 days. The effect was varied depending on the amounts of Gatt, but Dongchimi fermented with 5% Gatt was most favored for color, flavor, taste, and overall acceptability in sensory evaluation. According to the quantitative descriptive analysis for the product, the liquid portion of Dongchimi steadily became clearer and less sour in proportion to the amount of added Gatt. The fermentation retarding action of Gatt at the initial stage of Dongchimi fermentation was clearly seen as above. However, the addition of Gatt at above 15% of Chinese radish was not desirable due to the accelerated fermentation at the later stage. The general changing patterns in typical characteristics of fermentation including microbial counts were comparable with each other depending on the treatments. And favorable Dongchimi could be prepared by fermenting with 5% Gatt at the given condition.

• Food Science and Preservation
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• v.7 no.2
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• pp.222-227
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• 2000

Antimutagenic activity of crushed kimchi fermented with starter under various conditions such as temperature(5-20$^{\circ}C$), salt concentration(2-10%), addition rate of starter (0-20%) was investigated. The kimchi was fermented with crushed Chinese cabbage without salting, red pepper powder, crushed garlic, crushed ginger, anchovy juice and starter. Well fermented kimchi juice(fermented at 10$^{\circ}C$ for 15 days) and sterilized radish juice was used as a source of lactic acid bacteria and starter medium, respectively. Antimutagenic activity showed the highest in the crushed kimchi fermented at 15$^{\circ}C$ for 15 days, 4% salt concentration, 5% starter added, respectively. The inhibition rate of mutagenic activity of the kimchi against S. typhimurium TA98 induced by NQO and S. typhimurium TA100 induced by MNNG was 56.41% and 60.11%, respectively. And the inhibition rate of the kimchi juice showed 56-60% per 100ul.

• Culinary science and hospitality research
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• v.12 no.4 s.31
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• pp.299-319
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• 2006

The purpose of this study was to investigate the changes of hardness and microstructure of Dongchimi cooked with various sources of sugar(xylitol, xylose, sugar, pear juice). It was fermented at $10^{\circ}C$ for 60 days. The changes of pH in Dongchimi used different kinds of sugar decreased in all samples during the fermentation period, and then showed a slow decrease after 12 days of fermentation. The total acidity of Dongchimi using xylitol arrived slowly at the best tasting condition($0.3\sim0.4$ point) compared with other conditions. The changes of salt content were showed high as compared with other test conditions in 0 day, the day of fermentation. At the early stage of fermentation, the changes of turbidity of Dongchimi using sugar, pear juice were showed high as compared with those of Dongchimi using xylitol, xylose for $5\sim15$ days of fermentation. The maximum cutting force of Chinese radish Dongchimi showed the highest value among al at the 25 th day of ripening and then decreased gradually. The maximum cutting force of Dongchimi using sugar showed the lowest. The calcium and magnesium contents of Dongchimi juice and Chinese radish Dongchimi juice using xylitol were observed high at the early stage of fermentation and showed the highest value during the fermentation period. The microstructure showed disintegration appearance of middle lamella and cell wall during the fermentation period.