• Korean journal of applied entomology
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• v.48 no.4
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• pp.535-539
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• 2009

This study was conducted to identify plant-parasitic nematodes and determine the distribution pattern of the nematode species in citrus fruit orchards in Korea from April to August, 2008. Plant-parasitic nematodes were found in 139 among 178 soil samples. Tylenchulus semipenetrans was collected from 85 out of 94 Citrus unshiu orchards examined (90.4%). C. junos orchards infested with T. semipenetrans were 60 out of 84 (71.4%). However, proportion of dominant species between the two was different. At domestic Citrus orchards, it proved that T. semipenetrans was the most important plant-parasitic nematode from this study. The overall frequency of the plant-parasitic nematodes was positively correlated with the cultivation years. More alkaline soils tended to harbor more T. semipenetrans. However the correlation coefficient between the two was very low.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.137-143
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• 2010

Yuza (Citrus junos Sieb ex TANAKA) is a citrus fruit that is cultivated in northeast Asia. Citron is known for containing abundant antioxidants such as vitamin C, flavonoids, for example hesperidin and hesperetin, and terpenoids such as limononin. When mature citron is processed for tea or other beverage food products in Korea, massive amounts of seeds and pericarp are remained as waste. This study aimed to exploit the processed remnant of Citron for developing functional cosmetic applications. Ethanol extracts of Yuza seed and pericarp did not show significant radical scavenging activities measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. But they contained significantly high phenolic compounds. Cultured human dermal fibroblasts and HaCaT keratinocytes were irradiated with 25 mJ UVB and the citron extracts were added to the medium of each culture. Cellular damages caused by UVB irradiation were prevented by the addition of the Yuza extract. In addition, the reduction of the enhanced MMP-1 expression after irradiation of UVB in human dermal fibroblasts was observed. Also the increased level of pro-inflammtory TNF-$\alpha$ in the UVB irradiated HaCaT cells was decreased. The collagen expression was enhanced by the extract. Yuza extract markedly inhibited melanin production from $\alpha$-MSH treated B16F1 melanoma cells. Melanin assay, tyrosinase zymography results indicated that Yuza extract had strong depigmenting activity. In conclusion, Yuza ethanol extracts have good anti-photoaging and strong anti-melanogenic efficacies.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.113-119
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• 2005

Objectives : The purpose of this study is to determine new source of Jisil(枳實). Methods : Find out the source of Jisil in the history of herbal medicine. Results : 1. The source of jisil(枳實) is known as the immature fruit of Poncirus trifoliata Rafinesqul(Rutaceae) in the Korean Pharmacopoeia Eight Edition, the dried young fruit of Citrus aurantium L. and its cultivars or Citrus sinensis Osbeck(Fam. Rutaceae) in Pharmacopeia of the people's republic of china(English edition 2000). 2. Until Song dynasty, Jisil is the pericarp of the ripe fruit of Poncirus trifoliata 3. From Myeong dynasty the source of jisil(枳實) turn to the immature fruit of C. wilsonii, C. junos, C. aurantiun var. amara Conclusions : The source of Jisil(枳實) is the ripe fruit of Poncirus trifoliata.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.197-201
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• 2006

Long-term storage technology was developed to extend shelf-life of citron (Citrus junos). Changes in quality characteristics of blanched and frozen citron peels (type A, without blanching for control; type B, blanched at $95^{\circ}C$ for 2 min; type C, blanched at $95^{\circ}C$ for 2 min, sugar added; type D, blanched at $95^{\circ}C$ for 5 min) during frozen storage were evaluated. Citron jam was prepared using frozen citron sample B, which showed the highest quality characteristics during storage, and high quality characteristics, such as yield and overall acceptability, were obtained when using 40% frozen citron, 41% sugar, 18.56% glutinous starch syrup, 0.39% pectin, and 0.05% citric acid. During storage of both blanched and frozen citron peels and citron jam made of frozen citron peel, changes in characteristics such as pH, total acids, soluble solids, and browning, were lower than those of control. Sensory evaluation for sourness, sweetness, and overall acceptability of citron jam made with frozen citron peel during storage showed higher values than those of control.

• Journal of Food Hygiene and Safety
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• v.19 no.3
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• pp.126-131
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• 2004

This study was conducted to investigate of inhibition activity of yuza (Citrus junos) extracts and juice on nitrite scavenging and N-nitrosodimethylamine (NDMA) formation in model system. Yuza juice was separated into organic acid, ascorbate and phenolic portion using sep-pak $C_{18}$ cartridge, respectively. Nitrite scavenging activity and inhibition of NDMA formation from yuza extract has shown higher inhibition with pH of reaction condition lower and amount of added sample more. And peel extract of yuza was higher than those of flesh extract. Nitrite scavenging activity was excellent juice portion rather that 3 portions. Of the 3 portions, it activity was the highest in the organic acid portion, and decreased in the following order; phenolic acid, ascorbate portion. Therefore, organic acid of yuza was suggested to expect effective ihhibitor of NDMA formation.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.286-292
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• 1997

The purpose of this study was to investigate the effect of citron (Citrus junos) on Dongchimi (watery radish kimchi) fermentation. Dongchimi with various levels (0, 1, 2, 4, 6％) of citron was fermented at 10$^{\circ}C$ for 36 days. The pH of Dongchimi decreased slowly in all samples during fermentation, however, it was slightly lower in citron-added Dongchimi. Total acidity and turbidity of Dongchimi increased gradually during formentation, in which the level of increase was greater as the ％ of added citron increased. However, the total acidity and turbidity of Dongchimt without citron increased dramatically on 36$\^{th}$/ day of fermentation, and reached the values similar to those of Dongchimi with 6% citron. Reducing sugar content increased gradually up to 15∼23 days of fermentation and decreased rapidly for the rest of the period. The content of vitamin C was much higher in citron-added Dongchimi, and especially it was 4 times higher than that of without citron at the beginning of fermentation. The number of lactic acid bacteria reached the maximum on 15$\^{th}$/ day in citron-added Dongchimi and on 30$\^{th}$/ day in Dongchimi without citron, and decreased thereafter.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.419-427
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• 2020

The purpose of this study was to investigate the qualitative changes of the citron by identifying the type of solution and addition of the solution to prevent the browning reaction of the citron in a way that inhibits the browning of the citron. The browning inhibitor solution was investigated using the individual and mixture, and the results of the degree of browning and chromaticity showed that vitamin C+NaCl+cyclodextrin (CD) had the lowest browning of 0.52. In chromaticity, the ΔE values indicate that the higher the value, the greater the change in color, and the lowest value of the vitamin C+NaCl+CD mixture was 47.0, indicating that there was minimal browning compared to other treatment. The active change of the polyphenol oxidase (PPO) in the citron increased enzyme activity as the browning progressed, and the vitamin C+NaCl+CD solution was the lowest at 68.40 μ/g among the anti-browning solution. Based on these research results, it seems that the CD mixing solution can be used as a citron browning inhibitor.

• The Plant Pathology Journal
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• v.16 no.1
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• pp.48-51
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• 2000

Citrus tristeza virus (CTV) was identified form CTV-infected early satsuma mandarin (Citus unshiu) and yuzu (C.junos) by RT-PCR. The total RNAs were isolated from citrus bark and seaf tissues infected with CTV and reverse transcription was followed with primers designed for amplifying CTV coat protein gene. DNA fragments 738 bp were amplified by RT-PCR and these products were colned for sequence analysis. Based on the sequence analysis, this PCR product has 97% sequence homology to CTV (T-385) CP gene isolated from USA. RT-PCR assay for CTV detection was more sensitivity than ELISA assay which was done with anti-CTV CP antibody. This is the frist report about CTV identification in Cheju island Korea.

• Applied Biological Chemistry
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• v.15 no.2
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• pp.169-173
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• 1972

In five varietes of Citrus junos sieb grown in different area in Korea, the general components, total acids and inorganic components were calculated and compared with one other. In the orchard soils, the physical and chemical properties were studied. The results are summarized as follow: 1. Generally, the rind was weighter than tile flesh compared with the other fruits and the proportion of the rind was 49%. 2. Total contents of organic acids in rind and flesh were 12.29me and 39.79me respectively. 3. The order of the contents of inorganic components in the flesh and rind was $CaO>K_2O>MgO>P_2O_5>SO_4$ 4. The contents of crude protein and crude fat were increased with those of MgO and $SO_4$ in fruits. 5. The quantity of protein in the soil seed to influence greatly in rind formation not only in citrus fruits but also Citrus junos sieb. 6. In growing Citrus junos sieb, C.L. seemed to he the most adequate soil. 7. The pH range of the soil was from 5.05 to 7.20 generally. 8. The contents of crude protein and crude fat in citrus fruits seemed to be increased with those of organic material and total-nitrogen in the soil.

• Journal of Applied Biological Chemistry
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• v.50 no.3
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• pp.148-154
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• 2007

Volatile components of the essential oils of Satsuma mandarin (C. unshiu), Dangyuza (C. grandis), Yuza (C. junos), Byungkyul (C. playtymamma), Jinkyul (C. sunki), and Hakyul (C. natsudaidai) grown in Jeju Island were isolated from the fruit peels by hydro distillation and determined by GC-MS. GC-MS analysis identified 58 compounds, with main components being d-limonene $(64.01{\sim}79.34%),\;{\beta}-myrcene\;(3.01{\sim}26.53%),\;{\gamma}-terpinene\;(0.11{\sim}12.88%),\;{\beta}-pinene\;(0.78{\sim}4.74%),\;and\;{\alpha}-pinene\;(1.01{\sim}2.55%)$. Differences in compositions and contents of the essential oils were observed among citrus varieties. Effects of citrus oils on growth inhibitions of Escherchia coli, Staphyllococcus epidermidis, and Candida albicans were investigated using disc diffusion assay and minimal inhibitory concentration (MIC) assay. The essential oils inhibited growths of the test organisms, exhibiting higher levels of activity against Gram-positive S. epidermidis (MIC values $0.04{\sim}0.17mg/mL$), whereas Gram-negative E. coli was moderately resistant (MIC values $1.66{\sim}20.30mg/mL$). MIC of citrus essential oils ranged from $0.82{\sim}23.69mg/mL$ against C. albicans. The essential oils obtained from C. sunki, C. grandis, and C. playtymamma showed the highest antimicrobial activities against S. epidermidis and C. albicans, indicating their potential as natural antimicrobial agents.