• Korean journal of food and cookery science
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• v.3 no.1
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• pp.64-70
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• 1987

The effects of salting on the compositional and textural changes of Korean cabbage were studied. The optimum brining conditions were established ana the dietary fiber composition, mineral contents and moisture content of raw and salted Korean cabbage were determined. The cutting test of cabbage was made by Rheometer and the brittleness and chewiness were evaluated organoleptically. The optimum condition for brining was at 20% NaCl concentration for 6 hours. In the compositional changes of Korean cabbage by salting at 20% NaCl solution for one month, the content of hot water soluble pectin (HW-P) increased from 43.6% to 55.9% and that of hexametaphosphate soluble pectin (HM-P) decreased from 35.9% to 29.5%. The contents of cellulose and hemicellulose increased, but that of lignin decreased slightly by salting, showing no significant differences in raw and salted cabbage. The content of Na increased significantly and those of Ca, Mg and K decreased by salting. And also moisture content decreased from 91% to 79%. In the textural changes of Korean cabbage by salting, the maximum cutting force and cutting work increased five times and two and half times respectively. And organoleptic test did show significant increase in chewiness and decrease in brittleness. The maximum cutting force by Rheometer was well correlated with the sensory parameters. The results taken together showed that the changes in textural properties during salting are relevant to the changes in pectic substances, moisture content and mineral contents, but relatively irrelevant to the changes in cellulose, hemi-cellulose ana lignin. And it is considered that the maximum cutting force by cutting test is good means for the expression of texture of Korean cabbage.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.125-133
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• 2015

Entomopathogenic fungi have been studied to develop for biological control agents as an alternative to chemical control agents in insect pest management. Two Lepidopteran insects, Spodoptera exigua and Plutella xylostella, are serious insect pests infested various crops, but not effectively controlled by commercial chemical pesticides due to its high insecticide resistance. A fungal isolate was isolated from S. exigua larvae collected from green onion field in Andong, Korea. To identify the fungal isolate, 18srRNA sequence for internal transcribed spacer (ITS) and ${\beta}$-tubulin regions were sequenced. The ITS and ${\beta}$-tubulin sequence were highly matched to Beauveria bassiana and morphological characteristics also was fit to known B. bassiana. Finally, isolated fungus has identified as B. bassiana and named B. bassiana ANU1. The result of bioassay, median lethal concentrations were $2.7{\times}10^3$ and $0.9{\times}10^3conidia/ml$ and medial lethal times were 65.6 and 60.8 h to S. exigua and P. xylostella, respectively. B. bassiana ANU1 showed high pathogenicity to two insect pests from $20^{\circ}C$ to $30^{\circ}C$ at 50% relative humidity (RH) and more than 40% RH at $25^{\circ}C$ with $10^7conidia/ml$ of concentration.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.25-30
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• 1993

It is common that in the vegetable cultivation areas, the farmers tend to continue the heavy fertilization to maximize the crop yields in short term. This results in the accumulation of fertilizer elements in the soil and increase in the electrical conductivity of soil. Disregarding these, farmers continue to apply heavy doses of fertilizers. A field experiment was conducted to find out on such a soil whether fertilizer application taking the quantity of nutrients accumulated in the soil into account would save the fertilizer without losing the yield of crop, using Chinese cabbage and spinach as test crops. The findings of the experiment is summarized as following. 1. The yield of Chinese cabbage was not affected by reduction of $19kg\;P_2O_5/10a$ and $7kg\;K_2O/10a$ as compared to farmers doses, and in case of spinach the yield rather was increased under the reduction of $22kg\;P_2O_5/10a$ and $22kg\;K_2O/10a$. 2. The reduction of fertilizers according to plant nutrient status of soils did not affect the inorganic nutrient contents of the crops significantly, in both Chinese cabbage and spinach. 3. A trend was observed that the reduction in the P and K fertilizers application would shorten the storage period of Chinese cabbage. 4. The reduction in P and K fertilizers application resulted in the reduction in available P, exchangeable K, EC and $NO_3-N$ in the soil after the harvest of the crops.

• Research in Plant Disease
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• v.19 no.3
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• pp.201-207
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• 2013

This research was performed to establish basic technology for Chinese cabbage clubroot chemical control by investigating the soil contamination of Plasmodiophora brassicae in major producing regions of fall Chinese cabbage. PCR primers were developed to detect P. brassicae, a causal agent of Chinese cabbage club-root that generally occurs in Cruciferae family. A primer set, PbbtgF761 and PbbtgR961, specifically amplified a 245 bp fragment from P. brassicae only. At places well known for fall Chinese cabbage, 10 out of 33 in Haenam-gun, 5 out of 13 in Yeongam-gun and Yeonggwang-gun, 1 out of 6 in Gochang-gun, 2 out of 12 in Hongseong-gun, and 5 out of 17 in Dangjin-si resulted positive for P. brassicae contamination. The results show that the soil contamination rate of P. brassicae was 30.3% in Haenam-gun, 38.5% in Yeongam-gun and Yeonggwang-gun, 16.7% in Gochang-gun, 16.7% in Hongseong-gun, and 29.4% in Dangjin-si. The six places where Chinese cabbage clubroot was visible by naked eye were 100% confirmed by the PCR test of the P. brassicae contaminated soil. Thus, simple PCR test may be utilized as an index to decide on chemical control of P. brassicae.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1715-1724
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• 2015

The combined effects of a sanitizer mixture solution and antimicrobial ice on the quality of salted Chinese cabbages were examined. Salted Chinese cabbages were treated with a sanitizer mixture (comprised 50 ppm aqueous $ClO_2$ and 0.5% citric acid), packed in 2% brine and antimicrobial ice, and stored for 12 days at 4 and $10^{\circ}C$. Microbiological data on the salted Chinese cabbages after washing with the sanitizer mixture indicated that the populations of total aerobic bacteria, and yeast and molds decreased by 2.20 and 1.28 log CFU/g after treatment with the sanitizer mixture. In addition, coliforms population of salted Chinese cabbage after 12 days storage at $4^{\circ}C$ in the combined mixture of the sanitizer and antimicrobial ice was 3.22 log CFU/g, which was a significantly different from that of control (5.46 log CFU/g). The combined treatment of sanitizer mixture, antimicrobial ice, and low temperature at $4^{\circ}C$ suppressed reduction of pH and elevation of titratable acidity, resulting in delaying the growth of lactic acid bacteria. Differences in salinity, hardness, and Hunter's $L^*$, $a^*$, and $b^*$ values among treatments were negligible during storage at $4^{\circ}C$. Therefore, this study suggests that a combination of sanitizer mixture, antimicrobial ice treatment, and low temperature storage could improve the microbial safety and quality of salted Chinese cabbages during storage.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.742-748
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• 1988

The macro-and microstructure of Chinese cabbage used for Korean Kimchi preparation were examined and the texture characteristics of raw cabbage leaf and salted or blanched leaves were evaluated by cutting test. The length and thickness of leaf stalk increased with the order of pyllotaxis, but the thinning effect of outermost leaves was observed. The microstructure of cut-profile of stalk showed densely compacted vascular systems aligned in the center of stalk and the outer space was filled with large parenchima cells. Due to this structure, characteristic cutting curves were obtained by cutting test, composing three peaks of cutting for inner surface skin, center vascular system and outer surface skin. Salting and blanching increased the cutting force mainly due to the increase of Gutted cell wall number caused by the structure collapse.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.89-92
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• 1982

Persistence of cyanofenphos on Chinese cabbage under the different climate conditions was studied by spraying the insecticide at the rate of 0.5 and 0.75 ㎏ AI/ha at 22 and 36 days after transplanting and monitoring its residues upto 35 days after the final spray. At both spraying rates the degradation patterns of the insecticide, regardless of climate condition, showed similar trends; cyanofenphos residues on Chinese cabbage declined rapidly upto 14 days after the final spray but more slowly thereafter. Half-life for cyanofenphos on Chinese cabbage was $6{\sim}7$ days. The half-life was little affected by the spraying rate and time. Based on the FAO/WHO maximum residue limit of cyanofenphos on common cabbage (2 ppm), it is recommended that the pre-harvest intervels of the insecticide on Chinese cabbage could be 16 and 19 days for 0.5 and 0.75 ㎏ AI/ha, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.75-82
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• 1987

This study was to investigate physicochemical and microbial changes that took place during the salting of chinese cabbages. Salinity(3%) that is suitable for kimchi preparation was reached when chinese cabbages were salted for seven hours in 10%, three hours in 15% and one hour in 20%. In the case of 5% it was not reached though they were salted for over twelve hours. In order to decrease salinity from 7% level of salted chinese cabbages to 3% level by soaking in tap water, 1.2 hours for leaf and three hours for patiole were spent. Volume, moisture, firmness and internal space of raw chinese cabbages were significantly decreased by salting (15%, 10 hours) : volume, 59.90%, moisture, about 31.92% and internal space rate, 35.06%. Contents of mono-and divalent cations$(K^+,\;Mg^{2+}\;and\;Ca^{2+})$ were reduced whereas $Na^+$ content was greatly increased; therefore, in the future the increase of Na-content remains open to question. By salting and washing, mold, yeast and bacteria were decreased by 58%, 40%, 45%, respectivity.

• The Korean Journal of Pesticide Science
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• v.13 no.2
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• pp.111-116
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• 2009

Juvenile hormone (JH) is an insect hormone mediating immature metamorphosis and adult reproduction. It also mediates immune responses to suppress hemocyte behavior, which is, however, activated by ecdysteroid. This study investigated an effect of a commercial pyriproxyfen (a JH agonist) formulation on a cellular immune response of the diamondback moth, Plutella xylostella, and analysed its mixture with Bacillus thuringiensis (Bt) in insecticidal potency. The commercial pyriproxyfen formulation significantly suppressed hemocyte-spreading behavior at low doses as did in pyriproxyfen technical grade. When the commercial pyriproxyfen formulation was mixed with Bt, Bt toxicity was significantly increased against P. xylostella larvae in laboratory. The mixture effect was then confirmed in field cultivating cabbage infested with P. xylostella larvae. The mixture showed a significantly enhanced mortality and reduced effective lethal time, compared to only Bt treatment.

• Research in Plant Disease
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• v.16 no.3
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• pp.279-284
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• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.