• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.109-120
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• 2011

Calyx-end browning in sweet persimmon (Diospyros kaki) fruits is the postharvest disorder during the storage and shows different proportions by the cultivars. This study was to evaluate fruit texture characteristics at harvest and to learn how browning in fruits affects the cell structures in different cultivars. Persimmon cultivars included 'Fuyu', 'Jiro', 'Uenishiwase', 'Daiandangam', and 'Ro-19', which were harvested at the end of October in 2003 and investigated after 100 days storage. Fruit texture varied with different cultivars. 'Jiro' and 'Ro-19' fruits did not have browning symptoms while 'Daiandangam' fruits had approximately 80% browning of them. There were no visual differences for the cell structure in fruit peels between fruits without browning, such as 'Jiro' and 'Ro-19', and fruits with browning, such as 'Fuyu', 'Uenishiwase', and 'Daiandangam'. The most outer layers in a 'Jiro' fruit peel arranged one to two epidermis which could not induce browning in the tissues, while 'Fuyu' had two to three layers, inducing a browning symptom. Although there were no differences for the tissue structure between browning and normal fruits, browning fruits did not have apparent cell organelle and proceeded degradation of cell walls in the flesh.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.206-212
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• 2009

We investigated the patterns of freeze injury in dormant 'Changhowon Hwangdo' peach fruit by observing the extent of browning and germination of the branches that were treated with freezing temperature sets simulating the process of natural freezing incidences in orchards. Under the treatment of freezing temperature of $-15^{\circ}C$, the browning ratios were 15% for flower bud and less than 3% for both leaf bud and cambium. Under the $-20^{\circ}C$ treatment, the browning ratios were 40% for both flower and leaf buds and 1% for cambium. The browning ratios were 86%, 68% and 40% respectively for flower bud, leaf bud, and cambium under the $-25^{\circ}C$ treatment. All the samples showed 100% browning ratio under the $-30^{\circ}C$ treatment. The budburst ratios of leaf buds were 85%, 66%, 32%, and 0% under the -15, -20, -25 and $-30^{\circ}C$ treatments, respectively. The branches of peach fruit treated with the same freezing temperature showed different responses depending on the sampling date. In January the browning ratio was low and the budburst ratio was high whereas in February the opposite was the case, showing vulnerability of peach trees to low temperature after endo-dormancy release.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.6
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• pp.118-125
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• 2011

This study was conducted to check danger of the cold injury by reviewing the lowest temperature by regions and the cold tolerance of Lagerstroemia indica and Pyracantha angustifolia. The cold tolerance of the samples treated at low temperature was evaluated by measuring electrical conductivity and observing browning of the cambium. It was proved that the lethal temperature of L. indica is below $-17.1^{\circ}C$, and that of P. angustifolia is below $-18.9^{\circ}C$. The frequency of the lowest temperature went down below $-17.1^{\circ}C$, was 7 times in Daejeon, 55 times in Cheongju and 72 times in Suwon for the last 45 years. In Daejeon, it has happened only once since 1975. The temperature dropped below $-18.9^{\circ}C$ 45 times in Cheongju and 32 times in Suwon during the same period, but it has not happened at all since 1991. It appears that the rising coefficient of the lowest temperature increases, as the latitude gets higher. As a result, L. indica and P. angustifolia which were planted in the central region of Korea, are considered in danger from freezing injury because the temperature can get very low intermittently in winter. But, the risk of freezing has reduced gradually as the lowest temperature raises each year.

• Food Engineering Progress
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• v.14 no.1
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• pp.27-34
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• 2010

Multilayer edible coatings was applied to lemon with beeswax-hydroxypropyl methylcellulose (BW-HPMC), soybean oil-carboxymethyl cellulose (SBO-CMC), and carnaubawax-shellac-locust bean gum (CW-SL-LBG), respectively. The multilayer was composed of two layers of the same material, but the outer layer only contained vitamins C and E as antioxidants. Coating amounts built on lemon peel were measured to be large in the order of CW-SLLBG> BW-HPMC> SBO-CMC. The coated lemons were stored at 30${^{\circ}C}$ for 12 days. CW-SL-LBG showed the least change during the storage in weight loss, rotten rate, firmness, and browning. Whereas SBO-CMC had the least change in pH, soluble solid amount, and titratable acidity. In a sensory test, CW-SL-LBG was evaluated to be the best in the attributes such as spoilage, glossiness, color, firmness, and flavor. Overall CW-SL-LBG was judged to be the best for multilayerd coating with vitamin C and E on lemon.

• Current Research on Agriculture and Life Sciences
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• v.15
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• pp.83-91
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• 1997

Phenolic acids are regarded as harmful materials in food and environment science. But recently, regarded as useful materials by their characteristics which bind metal ions and have pharmaceutical effect. It was necessary to remove or recover phenolic acids from solutIon containing phenolic acids. Continuous fixed-bed adsorption was adapted in order to separate phenolic acids from diluted solution and the breakthrough curve was predicted by nonlinear curve fitting method. The larger bed length showed the longer breakpoint time and the slow mass transfer coefficient. Ferulic acid among the phenolic acids was passed through the breakpoint first and the second and. third were p-coumaric acid and gallic acid. These orders were caused by not only ionic strength between adsrobent and adsorbate but also molecular weights.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.50-58
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• 1981

The influence of high temperature storage on the chemical composition and color intensity of the concentrated red ginseng extract(RGE) was investigated. The concentrated RGE was prepared by extraction of red ginseng tails with water and concentrated under reduced pressure. Changes in free sugars, saponin patterns and brown color intensity were measured during 96 hours of heat treatment at various temperature. A decrease in the contents of glucose, fructose and sucrose was resulted as the brown color intensity increased during the storage. The sugar contents and color intensity showed rapid initial change followed by slowing down at higher temperature. A significant relationship was found between sugar content and browning rate. The saponin pattern measured by high performance liquid chromatography, particularly in the region of protopanaxtriol, was also affected significantly. The peak heights of ginsenoside -Re and $-Rg_1$ were decreased while those of ginsenoside $-Rg_2$ and -Rh group were increased.

• Research in Plant Disease
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• v.25 no.2
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• pp.71-78
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• 2019

In 2018, severe diebacks have occurred on yuzu trees cultivated in Goheung, Jeonnam Province. On-farm surveys at 18 randomly selected orchards revealed the dieback incidence ranged from 7.5% to 100% with an average of 43.6%, and 56.6% of the affected yuzu trees were eventually killed. In order to find the reason for this sudden epidemic, we investigated the weather conditions that are exclusively distinct from previous years, hypothesizing that certain weather extremes might have caused the dieback epidemic on yuzu trees. Since different temperatures can cause freeze damage to plants depending on their dormancy stages, we investigated both periods when yuzu becomes hardy under deep dormancy (January-February) and when yuzu loses its cold hardiness (March-April). First, we found that daily minimum air temperatures below $-10^{\circ}C$ were recorded for 7 days in Goheung for January and February in 2018, while no occasions in 2017. In particular, there were two extreme temperature drops ($-12.6^{\circ}C$ and $-11.5^{\circ}C$) beyond the yuzu cold hardiness limit in 2018. In addition, another occasion of two sudden temperature drops to nearly $0^{\circ}C$ were occurred right after abnormally-warm-temperature-rises to $13^{\circ}C$ of daily minimum air temperatures in mid-March and early April. In conclusion, we estimated that the possible damages by several extreme freeze events during the winter of 2018 could be a major cause of severe diebacks and subsequently killed the severely affected yuzu trees.