• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.618-622
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• 1997

This study was carried out to investigate the effect of storage temperature (0, 5, $20^{\circ}C$) on chemical components of Korean kiwifruits. Moisture content decreased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples and slightly increased in $20^{\circ}C-stored$ sample. Soluble solid content increased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples and decreased in $20^{\circ}C-stored$ sample ranging from 11 to $14\;^{\circ}Brix$. pH and titratable acidity remained at the level of $3{\sim}3.5$ and $1{\sim}1.5$, respectively. The content of malic and quinic acid increased during storage at $0^{\circ}C$ and $5^{\circ}C$. In case of citric acid, the content increased up to 6th week and then decreased. Kiwifruits stored at $20^{\circ}C$ showed a changing pattern of organic acids similar to those stored at 0 and $5^{\circ}C$. Glucose, fructose and sucrose increased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples except fructose at $5^{\circ}C$. In case of $20^{\circ}C-stored$ sample, sucrose increased up to 2∼3th week and then decreased.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.4
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• pp.179-188
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• 2012

A kiwifruit cultivar 'Hayward' has been grown in Jeju Island where the current climate is suitable for growth and development of this crop. Prediction of the geographical shift in the phenology can help the kiwifruits growers to adapt to the local climate change in the future. Two phenology models (i.e., chill-day and DVS) were parameterized to estimate flowering date of kiwifruits 'Hayward' based on the data collected from field plots and chamber experiments in the southern coastal and island locations in South Korea. Spatio-temporally independent datasets were used to evaluate performance of the two models in predicting flowering date of 'Hayward'. Chill-day model showed better performance than DVS model (2.5 vs. 4.0 days in RMSE). Daily temperature data interpolated at a higher spatial resolution over Jeju Island were used to predict flowering dates of 'Hayward' in 2021-2100 under the A1B scenario. According to the model calculation under the future climate condition, the flowering of kiwifruits shall accelerate and the area with poor flowering might increase due to the warmer winter induced insufficient chilling. Optimal land area for growing 'Hayward' could increase for a while in the near future (2021-2030), whereas such areas could decrease to one half of the current areas by 2100. The geographic locations suitable for 'Hayward' cultivation would migrate from the current coastal area to the elevated mountain area by 250 m.

• Korean journal of applied entomology
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• v.33 no.3
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• pp.148-152
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• 1994

This study was carried out to investigate insect specles of Kiwi fruit, and ecological characteristicsof Stathmopoda m Chonnam province from 1991 to 1993 Twelve families and thirteen specieswere identified during the study. Sfothmopoda aurijerello and mulberp scale were key insect pestsamong them. The body sizes of each stage of S. a~irijereilo was measured and found to be 0.12 mmfor egg, 9.8 mm for mature lawa. 5.9 mm for pupae and 123mm for adult with opened wings.S, ouriferelia appers to have two generations a yea Adults occut~ed from late May to midJulyand mid-August to early September Mth two peaks m early to midJune and late August. Changein age structure (% lawe: % pupae) over time was 100: 0 in earlyJul, 96. 1 . 3 9 in midduly. 64.9:35 1 in late July. 19.8 . 80 2 in early August, and 0 : 100 in mld-August Damaged fruit was 4 6%in early July, increase above 40% 1" midJuly, and then the damage surpassed the damage threshold.The rate of fruit damaged was 45.9%, and there wbi no significant dtfferences among countiesDamaged parts of fruits were manly fruit apex Mth 70% and followed by fruit stalk w~th 11.1%.The rate of fruit damaged by varieties were Hayward with 25.7%. Monty with 17 5%. Hyangrokwith 13.9%, Abott with 9.3% and Bruno with 6.0%. with 9.3% and Bruno with 6.0%.

• Korean Journal of Food Science and Technology
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• v.42 no.6
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• pp.664-675
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• 2010

This survey was carried out to estimate pesticide residue levels in commercial agricultural products in the year 2009. Residues were examined in 16 commodities (rice, foxtail millet, buckwheat, kidney beans, peanuts, sesame, oranges, grapefruit, kiwifruit, spinach, perilla leaves, leeks, garlic stem, garlic, ginger, and oak mushroom) collected from 22 provinces in Korea. Analyses were performed by multi-methods capable of detecting up to 60 pesticides by LC/MS/MS. A total of 510 samples were collected and analyzed. Of the samples, 96.1% contained no detectable pesticide residues. Detectable residues at or below the MRLs were found in 3.5% of the samples. However, in 0.4% of the samples (spinach and leeks), residue (ethaboxam and fluquinconazole) levels exceeded the MRLs. Furthermore, intake assessments of 7 kinds of pesticide residues were carried out, excluding those exceeding the MRLs. The results showed that the ratios of EDI (estimated daily intake) to ADI (acceptable daily intake) were 0.0001-0.0006%, which indicates that the detected pesticide residues were in a safe range. It is concluded that residual pesticides in agricultural products are properly controlled in Korea.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.547-555
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• 2021

A catalyst-plasma reactor was applied to the storage of agricultural products, e.g., apple and kiwi, to remove the ethylene generated during the storage. Two 1-m³ unit containers were prepared, and the long-term storage stability of the control group at room temperature was compared with that of the experimental group of which the produced ethylene was treated by the catalyst-plasma reactor. In case of the experimental group, a small amount of ozone was injected to the unit container to suppress the growth of microorganisms such as mold. The apples and kiwis were stored at room temperature for 50 and 57 days, respectively, and the changes in ethylene concentration, hardness, sugar content, acidity, and loss rate were compared. The ethylene concentration during the storage for the control group was higher than that for the experimental group, indicating that the ethylene was effectively removed. Hardness, sugar content, and sugar acid ratio after the storage were better than before the storage, and in particular, the storage stability of kiwifruit was improved significantly. In addition, after the storage, the loss rates of apples and kiwis in the control group were 10 and 54.1%, respectively, but the loss rates in the experimental group were 6 and 34.8%, respectively. Therefore, the storage stability of the experimental group was a lot better than that of the control group.