• Korean journal of applied entomology
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• v.51 no.1
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• pp.1-7
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• 2012

Silver-grey or dark brown scaring, or dark brown discolored damages caused by the yellow tea thrip, $Scirtothrips$ $dorsalis$ Hood (Thysanoptera: Thripidae) have occurred on citrus fruits cultivated in the open field in east-south area orchards of Jeju Island since 2007. The weekly population of yellow tea thrips adults caught with a yellow sticky trap increased gradually from early May and peaked in late August, 2009. In 2010 and 2011, the most population was in early October. The yellow tea thrips of some species usually dominated from July in open citrus fields, and seven generations, at least, had occurred from May to late October 2009 by a yellow sticky trap survey. In 2009, $S.$ $dorsalis$ larva were observed from July and with peaks from late August to mid September and early October on citrus fruits. The damage symptoms appeared in the mid September. In 2011, the population peaks were in early July and late September, and the symptoms increased continually from mid July to late October. The symptoms were silver-scars or initial dark discolorations and then gradually changed to dark-brown discolorations or dark-brown scars. The percent of damaged fruits were 0.9%, 0.4%, 0.8% and 2.7% in 2008, 2009, 2010 and 2011, respectively, by survey in 64 typical orchards in Jeju Island. We are the first to report symptoms of the yellow tea thrip ($Scirtothrips$ $dotsalis$) on citrus fruits.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.392-402
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• 2018

Citrus fruits can be classified as field citrus, greenhouse citrus, citrus produced by rain proof cultivation and late-harvested citrus such as Hallabong, Chunhaehyang, and Jinjihyang according to cultivation method or variety in Jeju province of Korea. The consumption of late-harvested citrus has been increasing steadily since 1990 because the sugar content of the fruits is ordinary higher than field citrus. The cultivation land of citrus produced by rain proof cultivation has been also enlarged continuously aided by Korean government support program and quality increasing effect of this cultivation method. However, the cultivation land of field citrus has been decreasing since 2010. In spite of such a decrease of cultivation land, recently the price of field citrus rather declined according to increasing of yield per 10a. For the estimation and forecast of the long-term supply-demand model in the field citrus, we constructed a partial balance model for the individual field citrus and estimated individual equation in each item's model by using the econometric method. As a result of the production storage scenario analysis, the cultivation area is expected to store 5%(14.49ha), 10%(14.97ha). 15%(15.50ha) of citrus production in 2027. This study reviews the structure of storage, and storability in Jeju field citrus and suggest several policy implications.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.158-162
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• 1984

In order to estimate the basic data for the processing suitability of fruits, the contents of free sugars in citrus fruits(14 varieties) cultured in Jeju island, and peaches(4), grapes(4), pears(3) and apples(6) obtained from a local market were investigated by HPLC. The sucrose was the most abundant sugar in citrus fruits and peaches, and followed by fructose and glucose in order. The sugar contents in citru fruits was a wide difference according to the variety. In citrus fruit, the sucrose content was about 53 to 65% to total free sugars and the ratio of fructose to glucose was 1.0/0.8-1.1. The sugars present in grapes and pears were fructose of most abundance, glucose and sucrose in order. Jangshiprang pear showed 2 times higher fructose content than other variety. The free sugar in Taeyang and Hongok(Jonathan) apples were fructose, glucose and sucrose in order of abundance which fructose, sucrose and glucose in Golden Fuji and Mutsu.

• Journal of Life Science
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• v.24 no.4
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• pp.454-460
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• 2014

In a previous study, we found that methanolic extracts of immature fruits of Satuma mandarin (Citrus unshiu Marc. var. okitsu) contained relatively high amounts of phytochemicals. Here we show that a combined treatment consisting of immature fruits of Satuma mandarin and cisplatin induced strong apoptotic response in human melanoma A375 cells. We further investigated the mechanisms by which immature fruits of Satuma mandarin augment cisplatin-induced apoptosis in A375 cells. Satuma mandarin up-regulated the expression of nitric oxide synthase (NOS), elevated nitric oxide ($NO^{\cdot}$) production, and weakening the anti-apoptotic signals inhibitor of apoptosis (IAP) family, thus facilitating the process of apoptosis. These results suggest that immature fruits of Satuma mandarin in combination with cisplatin might have therapeutic value in melanoma treatment worthy of further development.

• The Korea Journal of Herbology
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• v.22 no.3
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• pp.109-116
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• 2007

Objective : In order to elucidate hyperlipidemic effects of the fruits of Poncirus trifoliata and Citrus aurantium, our experimental study was performed on hyperlipidemia rats induced by Triton WR-1339. Method : The hyperlipidemia rats induced by intraperitonial injection of triton WR-1339 were treated with the fruits of P. trifoliata (rare and preparata) and C. aurantium 50 and 200mg/kg. The amount of triglyceride. total cholesterol. HDL-cholesterol, LDL-cholesterol, AST. and ALT levels were measured. Results: The levels of triglyceride. total cholesterol and LDL-cholesterol were significantly reduced in fruits of P. trifoliata (rare and preparata) and C. aurantiu. Simvastatine treated group compared with those of control but the level of HDL-cholesterol was incresed. The level of AST and ALT were not significantly reduced by the treatment to the fruits of P. trifoliata (rare and preparata) and C. aurantium. Conclusion : In the hyperlipidemia rats induced by triton WR-1339. the fruits of P. trifoliata (rare and preparata) and C. aurantium showed a hyperlipidemic effect.

• Korean Journal Plant Pathology
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• v.14 no.4
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• pp.303-307
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• 1998

Citrus scab caused warty and scabby lesions on the surface of leaves, twigs and fruits of Satsuma mandarin. Warty lesions were mainly developed before July but scabby ones were developed during summer season in Cheju island, Korea. The casual organism of scab was morphologically identified as Sphaceloma fawcettii and was thought to be Tryon's pathotype of Elsinoe fawcettii, because it was pathogenic on rough lemon and Cleopatra mandarin but non-pathogenic on sour orange, grapefruit and sweet orange among the 5 differential hosts of E. fawcettii.

• Food Science and Preservation
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• v.8 no.3
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• pp.279-285
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• 2001

The effect of chitosan and cacium treatment on the quality of satsuma mandarin(Citrus unshiu Marc. var. miyagawa) during storage were investigated. Citrus fruits treated with 2000-folds diluted iminoctadime-triacetate solution or 1.5% chitosan with 0.5% CaCl$_2$ solution were stored at 4$\^{C}$ and 87$\pm$3% relative humidity, and room temperature without humidity control. Decay ratio of chitosan and calcium treated fruits were lower than the ones with no treatment from the mid of February. Also, citrus fruits treated with chitosan and calcium treated less in weight loss, that seems it was derived from restraining of fruits' transpiration. Soluble solids were maintained higher level in chitosan and calcium treated fruits than with no treatment during the storage. Acid contents were decreased gradually lower in cold storage than in room temperature storage, and there was not showed consistent trend among treatments. 26 kinds of free amino acids among 45 standards such as glutamic acid, threonine, serine, alanine γ-amino buryric acid, aspragine and etc were detected in Citrus unshiu Marc. var. miyagawa. As the storage time was prolonged, free amino acid was disappeared more or less, and the deccreasing extent was less in 4$\^{C}$ than in room temperature storage.

• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.409-415
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• 2013

Post-harvest fungicide residue was measured in citrus fruits. Samples were collected from local markets in Seoul and analyzed using liquid chromatography coupled with mass spectrometry (LC-MS). LC-MS results were validated for the assay of pesticides by using linearity, accuracy, precision, and limits of detection and quantification. The linearity in the concentration ranged from 0.005 to 2.0 mg/kg ($R^2$ >0.999). Sample recoveries ranged from 80.2 to 98.3% with relative standard deviations below 4.0% for spiking levels from 0.01 to 1.0 mg/kg. The limits of detection ranged between 0.002 and 0.008 mg/kg, and the limits of quantification ranged between 0.006 and 0.027 mg/kg. The highest residue levels for carbendazim, thiabendazole, imazalil, and azoxystrobin in citrus fruits were 0.541, 0.958, 0.721, and 0.052 mg/kg, respectively. The pesticide residues found in citrus fruits were blow maximum residue limits (MRLs) and are not a serious public health problem.

• Korean journal of applied entomology
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• v.39 no.4
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• pp.267-274
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• 2000

As the pest of the citrus in Cheju, 69 insect species and 5 animal species were investigated during 1996 to 1998. Of these, Panonychus citri, Phyllocnistis citrella, Aphis citricola, Aphis gossypii and Frankliniella occidentalis are major pests. Especially, F. occidentalis and Peridroma saucia are very important species because of increasing damage. The number of pests species injuring leaf, branch, fruit and flower of the citrus are 36, 16, 41 and 2 species respectively. The rate of damaged fruits by pests is 20.5% in 1997 and 18.6% in 1998 and the rate of bad quality fruits is 6.4% and 6.7% respectively.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.1-4
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• 2002

Eleven flavonoids, including rutin, naringin, hesperidin, neohesperidin, quercetin, naringenin, kaempferol, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone and tangeretin in the peel of late maturing citrus fruit species of Mucott (smith tangerine), Singamha (C. natsudidai), Sambogam (C. sulcata), Hongpalsak (C. hassaku), Seminol (Dancy tangerine) and Jawdung (C. aurantium) harvested during from August to December were analyzed with HPLC. The mobile phase consisted of water and acetonitrile with 0.5% acetic acid. Wavelength in UV detector was determined at 254 nm. Naringin and neohesperidin content in the peel of Jawdung harvested at the early stage of maturation were 34.02 mg/g and 13.68 mg/g, respectively, and it was highest among the tested citrus fruits. Hesperidin content in the peel of Mucott harvested at the earthy stage of maturation was 12.48 mg/g. Rutin content of Sambogam harvested at the early stage of maturation was 5.13 mg/g. Quercetin, naringein, kaempferol, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone flavonoids were in trace. Flavonoid contents of Singamha, Sambogam and Jawdung were high in the peel of fruits at the early stage of maturation, after which time they decreased rapidly.