• 한국식품저장유통학회지
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• 제3권1호
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• pp.23-32
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• 1996

Total carotenoid contents, color values and spectrum characterization in the range of UV of fruit juice and organic acid and free sugar contents determined by HPLC were investigated on 10 varieties of Cheju citrus fruits. Carotenoid contents of juice were 0.47-9.20$\mu\textrm{g}$/ml which showed higher with Dangyooja while showed lowest content with Meiwa Kumquat. Lightness (L) of juice was highest in Meiwa Kumquat, and in the order of Sankyool, Navel orange and Hungjin. Redness(a) and yellowness(b) were in the order of Dangyooja, Natsudaidai, Sambokam and Kinkoji. The maximum absorption wavelengths if citrus Juices were variable at 269.5-285.5nm according to varieties and it was observed that were changed by mixing with Juices of other varieties. Major organic acids of citrus juice were citric and malic acid, and citric acid was 64.4-95.1% of total organic acids. Ascorbic acid was high in Navel orange, Sudachi and Dangyooja, and low in Meiwa Kumquat and Hungjin. Major free sugars were sucrose, glucose and fructose. Sucrose was 49.2-75.2% of total free sugars, and high in Sankyool and Meiwa Kumquat. Glucose and fructose were high in Meiwa Kumquat and Navel Orange.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.271-279
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• 2004

The aroma component of Hallabong peel has been characterized by GC-MS with two different extraction techniques: solid-phase trapping solvent extraction (SPTE) and headspace solid-phase microextraction (HSSPME). Aroma components emitted from Hallabong peel were compared with those of other citrus varieties: lemon, orange and grapefruit by SPTE and GC-MS. d-Limonene (96.98%) in Hallabong was the main component, and relatively higher peaks of cis- ${\beta}$-ocimene, valencene and -farnesene were observed. Other volatile aromas, such as sabinene, isothujol and ${\delta}$-elemene were observed as small peaks. Also, principal components analysis was employed to distinguish citrus aromas based on their chromatographic data. For HSSPME, the fiber efficiency was evaluated by comparing the partition coefficient ($K_{gs}$Kgs) between the HS gaseous phase and HS-SPME fiber coating, and the relative concentration factors (CF) of the five characteristic compounds of the four citrus varieties. 50/30 ${\mu}$m DVB/CAR/PDMS fiber was verified as the best choice among the four fibers evaluated for all the samples.

• Applied Biological Chemistry
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• 제22권1호
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• pp.28-32
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• 1979

증산되고 있는 한국산 온주계통 감귤의 품질향상을 도모하여 새로운 수요를 개발하기 위한 목적의 일환으로 제주산 감귤의 품종별 가공특성 조사를 실시하였다. 1. 과실 맛의 주체라고 할 수 있는 당도는 $9.0{\sim}10.0^{\circ}Bx$였고 산도는 $1.43{\sim}l.70%$로써 당산비는 $5.3{\sim}6.6$수준으로 비교적 낮은 품질 수준을 나타냈다. 2. 감귤 통조림의 백탁 현상의 원인이라고 알려진 과육의 hespeidin 함량은 조생종에 비하여 만생종으로 갈수록 낮아져 45mg%정도였다. 3. 외피율은 만생종이 될수록 높아져서 25%정도였고 착즙율은 50%이었다. 그러므로 저장에는 만생종이 유리하며 착즙율은 품종간에 큰 차이가 없었다. 4. 착즙액의 비중은 평균 1.040정도였고 혼탁도는 만생종이 될수록 높은 흡광도를 보였다. vit. C 및 hesperidin 함량은 $25{\sim}30mg%$를 유지하였다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.124-124
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• 2003

Citrus canker is very important disease in international trade of citrus. The disease was usually take place from late of June, and severe middle of July to middle of August, though disease occurrence was affected by environmental conditions. In pathogenicity test, three varieties, orange, lemon and kiyomi among 7 varieties, were succeptible, two varieties, satsuma mandarin and iwasachi, intermediate resistant. On the other hand, shiranuhi and yuzu were resistant relatively. The pathogen, Xanthomonas axonopodis pv. citri, grew well in PD broth adjusted to pH 7.0 at 26$^{\circ}C$. It's growth was best in medium containing group of monosaccharide as a carbon source and group of ammonium as a nitrogen source. Tow isolates were resistant to streptomycin among 11 isolates isolated from diseased leaves in field in Jeju-Do. The streptomycin sensitives isolate was controlled by in greenhouse test. On the other hand, the resistant and sensitive isolates were controlled by treatment with copper sulfate, the control value is 88.7％ and 90.6％, respectively.

• 한국식품저장유통학회지
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• 제2권2호
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• pp.259-268
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• 1995

Physico-chemical components which are closely related to processed products were investigated on 10 varieties of Cheju citrus fruits. Juice ratio of Hungjin was the highest, 49.2%, while Sankyool was the lowest, 4.2%, which showed great differences among varieties. Peel ratio of Dangyooja was the highest, 46.1%, while both Navel orange and Hungjin were relatively low. Soluble solid($^{\circ}$Brix) was relatively high In Sankyool, Meiwa Kumquat, Sambokam and Iyo. Acid content was the highest, 4.86% in sudachi and relatively high in Sankyool, Natsudaidai and Dangyooja. The $^{\circ}$Brix to acid content ratio was 13.9 in Meiwa Kumquat and more than 10 in Navel orange and Hungjin. Total sugar contents of Juice were 2.78∼10.94%, while reduced sugar contents were 1.63∼6.38% which showed higher in Meiwa Kumquat, Iyo and Navel Orange. Hesperidin and naringin, the sources of biiter taste and cloudness were low in Hungjin and Iyo. Soluble solid($^{\circ}$Brix) of citrus juice showed highest statistical relationship(r=0.907) with total sugar, and was highly significant at 1% level.

• 한국식품저장유통학회지
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• 제4권2호
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• pp.181-187
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• 1997

New HPLC method was developed for determination of some flavonoids such as naringin, hesperidin, neohesperidin, rutin, quercitrin, naringenin, hesperetin and apigenin and their contents in citrus juice and citrus peel from citrus varieties Brown in Cheju. Detection was at 280nm and reverse phase ${\mu}$-Bondapak C-18 column was used. Water/methanol/acetic acid as the mobile phase was better than water/acetonitrile/acetic acid. Flavonoids were more stable in 20% n,n-dimethylformamide in methanol(20% DMF) than methanol and pH 12 adjusted by 1N-sodium hydroxide solution. Standard flavonoid solutions were injected three times consecutively and the reproduciability was 0.236 to 3.550%, Correlation coefficient of the calibration curve was 0.9946 to 0.9999. The exiraction efficiency of hesperidin from citrus peel was evaluated with different extraction method such as reflux, ultra-sonicating method, using three solvents (aqueous solutions with pH12 adjusted by 1N-sodium hydroxide, methanol and 20% DMF), respectively. The reflux for 4 hour in 20% DMF was the most efficient of the tested methods and solvents, and recovery percentage were 78.0∼130.0%. Flavonoids were determined in citrus juice. Naringin was 68.2mg/100$m\ell$ in Natsudaidai, Hesperidin were 85.6mg/100$m\ell$ in Sankyool and Neohesperidin was 25.3mg/100$m\ell$ in Dangyooja. Flavonoids were determined in citrus peel. Naringin was 110mg/g in Dangyooja, Hesperidin was 242mg/g in Hungjin and Neohesperidin was 87.9mg/g in Dangyooja.

• The Plant Pathology Journal
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• 제15권6호
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• pp.335-339
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• 1999

Citrus tristeza virus(CTV), an aphid-borne closterovirus, is one of the most destructive pathogens of citrus. It has caused rapid decline in growth, stem pitting and death in citrus trees. A reverse transcriptase polymerase chain reaction (RT-PCR) assay was developed for detection of CTV and investigation of the CTV infection status of citrus and its related cultivars in Cheju island. For RT-PCR based CTV detection, primers were designed to amplify 670bp of coat protein gene. A screening test for CTV in citrus cultivars was conducted from March to July in 1999. Seventy individual citrus trees representing 9 species of 3 genera were tested. The infection rates of CTV for leaves from the years or older trees of late maturing citrus varieties such as Yuzu (C. junos Sieb. ex Tanaka), Navel orange (C.sinensis Osbeck), Kiyomitanger (C. unshiu x C. sinensis), and Shiranuhi ((C. unshiu x C. sinensis) x C. reticulata) were 100%, 80%, 60%, and 60% respectively. The CTV infection rates in Early satsuma mandarins such as 'Miyagawa Early' Satsuma mandarins (C. unshiu Marc. var. Miyagawa) and 'Okitsu Early' Satsuma mandarins (C. unshiu Marc. var. Okitsu) were 100%, and 60%, respectively. CTV was not detected in Cheju native Dangyooja (C. unshiu Marc. var. Osbeck), Trifoliate orange (Poncirus trifoliata) and Kumquat (Fortunella margarita Swingle). In conclusion, RT-PCR assay can be successfully applied to the detection of CTV in citrus trees.

• The Plant Pathology Journal
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• 제33권5호
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• pp.441-449
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• 2017

Citrus canker is an important bacterial disease of citrus in several regions of the world. Strains of Xanthomonas citri type-A (Xc-A) group are the primary pathogen where citrus canker occurs. After Xc-A entered the Northeast of Argentina in 1974, the disease spread rapidly from 1977 to 1980 and then slowed down and remained moving at slow pace until 1990 when it became endemic. Citrus canker was detected in Northwest Argentina in 2002. This paper presents the main steps in the fight of the disease and the management strategies that have been used to control citrus canker at this time. We think the process might be usefull to other countries with the same situation. Results from more than 40 years of research in Northeast (NE) Argentina indicate that we are at the limit of favorable environment for the disease. The severity of citrus canker is greatly affected by the environment and El $Ni{\tilde{n}}o$ Southern Oscillation (ENSO) phenomenon which causes cyclic fluctuations on the disease intensity in the NE region. Weather-based logistic regression models adjusted to quantify disease levels in field conditions showed that the environmental effect was strongly modulated by the distance from a windbreak. Production of healthy fruits in citrus canker endemic areas is possible knowing the dynamics of the disease. A voluntary Integrated Plan to Reduce the Risk of Canker has been in place since 1994 and it allows growers to export unsymptomatic, uninfested fresh fruit to countries which are free of the disease and require healthy, pathogen free fruits. The experience from Argentina can be replicated in other countries after appropriate trials.

• Applied Biological Chemistry
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• 제38권6호
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• pp.541-545
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• 1995

제주산 감귤의 표준시료에 대한 성분분석 및 그 특성을 검토하였다. 온주 밀감의 가용성고형물(Brix)은 $10.4{\sim}11.0^{\circ}$였고 총당은 $8.24{\sim}8.79%$였으며, 산함량은 $1.04{\sim}1.20%$였다. 비타민 C함량은 $41.19{\sim}46.55\;mg/100g$으로서 조생온주에 비해 보통온주에서 높았다. 온주밀감에서 무기물 함량의 경우 K가 $108.66{\sim}132.65\;mg/100g$으로 가장 많이 함유되고 있었으며, 잡감류의 경우는 온주밀감에 비해 무기물 함량이 높았다. 감귤쥬스 중의 당종류는 잡감류를 포함하여 품종에 따라 다소 차이가 있었으나 자당이 $46.8{\sim}64.6%$로서 가장 많이 함유하고 있었으며, 그외로는 포도당과 과당이 각각 $18.4{\sim}26.9%$과 $15.2{\sim}30.2%$로서 비슷한 수준이었다. 유기산 종류로는 구연산이 $75.7{\sim}96.2%$로서 대부분을 차지하였고, 그외로 malic acid, oxalic acid, fumaric acid 순으로 소량 함유되어 있었다.

• 한국식품과학회지
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• 제27권6호
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• pp.950-957
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• 1995

총 carotenoid 함량을 ${\beta}-carotene$ 상당의 mg%로 산출하였을 때 감귤 14종의 과육과 과피의 함량은 각각 $0.23{\sim}3.38\;mg%$, $0.82{\sim}10.64\;mg%$이었고 평균치는 과육과 과피에서 각각 1.5 mg%, 7 mg%이었다. HPLC에서 14종의 peak를 분리하였으며 이들 peak중 lutein, lycopene, ${\alpha}-carotene$, ${\beta}-carotene$은 표준품과 직접 비교 확인하였고, neoxanthin, violaxanthin, antheraxanthin, lutein-5,6-epoxide, isolutein, cryptox-diepoxide, cryptox-5,6-epoxide and ${\beta}-cryptoxanthin$ 등은 다른 문헌상의 $t_R$과 비교 추정하였다. 개별 carotenoid 함량비를 HPLC chromatogram의 peak 면적%로 비교하였던 바, 품종간의 차이는 뚜렷하지 않았다.