• Title/Summary/Keyword: Korean Citrus Industry

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Effects of Humidity and Citrus Leaf Age on the Multiplication of Aculops pelekassi (Acari: Eriophyoidea) and Seasonal Population Abundances in Citrus Orchards (습도와 감귤 잎의 연령이 귤녹응애 증식에 미치는 영향 및 감귤원에서 발생소장)

  • Seo, Yon Dong;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.53 no.1
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    • pp.1-6
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    • 2014
  • The pink citrus rust mite, Aculops pelekassi (Keifer) (Acari: Eriophyoidea), is an important pest in the citrus orchards of Jeju, Korea. This study was performed to investigate the seasonal population abundance of A. pelekassi, and the effects of humidity and citrus leaf age on the multiplication of this pest. Relative humidity (RH) significantly affected the longevity and fecundity of A. pelekassi. Longevity was 7.5, 14.5 and 14.6 d and fecundity was 5.4, 21.5, and 27.1 eggs at 33, 75 and 84% RH, respectively. The leaf age of citrus significantly affected the multiplication of A. pelekassi. The population abundance on 40 day-old leaves was much higher more than 3 times that on 10-day old leaves at 4 weeks after introduction. Overwintered A. pelekassi adults between the bud scales of the citrus trees became active in late April; they were found on newly emerged leaves, followed by their settlement on young fruits in mid-June. The population levels of A. pelekassi peaked on the leaves in late June to July, and on the fruits in early August. The results obtained in this study should be useful for the control of A. pelekassi in citrus orchards in Jeju.

Citrus Peel Wastes as Functional Materials for Cosmeceuticals

  • Kim, Sang-Suk;Lee, Jung-A;Kim, Ji-Young;Lee, Nam-Ho;Hyun, Chang-Gu
    • Journal of Applied Biological Chemistry
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    • v.51 no.1
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    • pp.7-12
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    • 2008
  • The suitability of CPWs, by-products of the juice industry, was investigated as a source for the production of cosmeceuticals. Four kinds of CPWs, CW, CWE, CWER, and CWEA, were examined for their antioxidant potentials in terms of DPPH radical-scavenging ability for anti-wrinkle applications, inhibition of tyrosinase or melanin production for whitening products, and anti-inflammatory effects to treat various skin diseases such as atopic dermatitis and acne as well as for anti-bacterial activity against acne-inducing pathogens. Of the four extracts, CWER was the most potent tyrosinase inhibitor ($IC_{50}$ value: $109\;{\mu}g/mL$), and CWEA ($IC_{50}:\;167\;{\mu}g/mL$) showed good antioxidative effects. CWE and CWEA samples had dose-dependent inhibitory effects on the melanin production. The cytotoxic effects of the four CPWs were determined by colorimetric MTT assays using human keratinocyte HaCaT cells. Most extracts exhibited low cytotoxicity at $100\;{\mu}g/mL$. These results suggest CPWs are attractive candidates for topical applications on the human skin.

A study on the Antioxidative and Antimicrobial Activities of the Citrus Unshju peel Extracts (감귤과피 추출물의 항산화 및 항균 효과에 관한 연구)

  • Ahn, Myung-Soo;Seo, Mi-Sook;Kim, Hyun-Jeung
    • Journal of the Korean Society of Food Culture
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    • v.22 no.4
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    • pp.454-461
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    • 2007
  • Antioxidative and antimicrobial activities were carried out on the Citrus Unshju peel solvent extracts in order to discover new functional activities. The amounts of polyphenol in 70% metanol extract (MtEx) was measured as 836.8 mg% in Citrus Unshju peel. The EDA (electron donating ability) of 0.01, 0.02 and 0.1% MtEx in Citrus Unshju peel were measured as levels of 81.3, 86.0 and 89.6%. The nitrite scavenging effects of Citrus peel were also determined as the levels of 34.4% (pH 1.2) and 19.5% (pH 7.0). The pH of react solution was more acidic, the nitrite scavenging effect was more increased. The order of antioxidatives was shown as TBHQ > BHT > TOC > ChEx > EaEx > EtEx > WaEx > Control in corn germ oil and TBHQ > ChEx > EaEx > BHT > EtEx > WaEx > TOC > Control in canola oil. A number of the extracts were certified to have antimicrobial activities for a small number of micro-organisms, similar gram negative and positive micro-organisms. According to the results above, it was summerized that Citrus Unshju peel had the higher total polyphenol, EDA, nitrite scavenging effects and antimicrobial activities. Also isolated extract from ChEx and EaEx had high antioxidative, these effects were very similar to that of ${alpha}$-tocopherol and BHT. It would be proposed that Citrus peel can become a new natural source for antioxidative agents in future food industry.

Effects of Feeding Citrus Byproducts on Nutritional Properties of Korean Native Chicken Eggs (토종닭 계란의 성분조성에 미치는 감귤부산물 급여의 영향)

  • Yang, Seung-Ju;Jung, In-Chul;Moon, Yoon-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.7
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    • pp.841-846
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    • 2008
  • In this study, the effects of feeding citrus byproducts on nutritional properties of Korean native chicken eggs were investigated. Two samples of Korean native chicken eggs were used for this study: T0 (Eggs of chickens that were not fed with citrus byproducts until they became 30 weeks old) and T1 (Eggs of chickens that were fed with 4% citrus byproducts when they were between 17 and 30 weeks old). There was nostatistically meaningful difference between T0 and T1 in terms of various properties, such as general components of egg albumen and yolk, total structural amino acid, and total free amino acid. Also, no significant difference was noticed between T0 and T1 in terms of various components of egg yolk, such as amount of mineral, vitamin, and xanthophyll, which showed that those components are not affected by citrus byproducts. However, the amount of cholesterol of egg yolk for T1 was 1,168 mg/100 g, which was significantly lower than that for T0 which was 1,207 mg/100 g (p<0.05). The amount of L-glutamic acid, one of the free amino acids, of the egg albumen was 39.22 and 58.54 ppm for T0 and T1, respectively. The results of this study show that citrus byproducts can be used for the feed for Korean native chicken by adding them to general feed.

Occurrence of Plant-Parasitic Nematodes on Ornamental Foliage Plants, Citrus Orchards, and Tea Plantations in Korea (국내 관엽식물 및 작물재배지의 식물기생선충 발생 조사)

  • Sungchan Huh;Namsook Park;Yongchul Kim;Insoo Choi
    • Research in Plant Disease
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    • v.29 no.4
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    • pp.459-463
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    • 2023
  • This study was conducted to investigate the plant-parasitic nematodes of ornamental foliage plants, citrus orchards, and tea plantations from July to December 2022. As a result of the investigation of plant-parasitic nematodes in 415 foliage plants, root-lesion nematodes were detected most frequently, followed by root-knot nematodes, pin nematodes, and other nematodes. In tea plantations, spiral nematodes, cyst nematodes, and root-knot nematodes were detected. Citrus nematodes, ring nematodes, and root-knot nematodes were discovered in citrus orchards. In foliage plants, tea plantations, and citrus orchards, the detection rate of plant-parasitic nematodes was not high, but root-lesion nematodes were detected. Therefore, it is necessary to apply appropriate control methods to manage root-lesion nematodes during the cultivation of foliage, tea, and citrus plants.

Frequency and Growth Characteristics of Polyploids Occurred Spontaneously in Some Mandarin Hybrids (만다린 잡종에서 자연발생 배수체의 발생 빈도와 생장 특성)

  • Song, Kwan-Jeong;Kim, Sat-Byul;Park, Jae-Hyun;Oh, Eun-Ui;Lee, Kyung-Uk;Kim, Dong-Wook;Kang, Jong-Hoon;Kim, Jeong-Soon;Oh, Jeong-Hwan;Gmitter, Fred G.
    • Horticultural Science & Technology
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    • v.29 no.6
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    • pp.617-622
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    • 2011
  • The study was conducted to determine the efficiency in producing spontaneous polyploids in some mandarin hybrids with different seed embryony. Seed formation by open pollination, frequency of spontaneous polyploids, and plant growth characteristics were evaluated in four mandarin hybrids with polyembryony such as 'Amakusa', 'Haruka', 'Hayaka', and 'Seminole' and two with monoembryony such as 'Benibae' and 'Harehime'. The mean number of the developed seeds per fruit was 10.0 and frequency of small seeds was 25.1%. Polyploids were selected from plants germinated in vitro by a flow cytometry and confirmed by chromosome analysis. One triploid was produced from 'Harehime', one tetraploid, 'Amakusa', and one tetrapoid, 'Benibae'. There were little differences in leaf shape, thickness, petiole length, and internode length between diploids and polyploids such as tri- or tetraploid. However, polyploids had larger stomata and lower density of stomata in abaxial epidermis than diploids. SPAS indicating chlorophyll content and photosynthetic rate were significantly affected by ploidy level. The results indicated that spontaneous polyploids might be produced by open pollination in some mandarin hybrids and monoembryony had higher frequency in polyploid occurrence than polyembryony.

Study on Diminution of Pesticide Residues in Citrus Fruits by γ-Irradiation (감마선 조사에 의한 감귤의 잔류농약 저감화 연구)

  • Yang, Hee Sun;Park, Yong Dae;Jin, Chang Hyun;Choi, Dae Seong;Jeong, Il Yun
    • Journal of Radiation Industry
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    • v.3 no.1
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    • pp.19-24
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    • 2009
  • The citrus fruits were irradiated at different doses (25~200 kGy) to remove pesticides such as diuron, dichlorbenil, trifluralin, dimetoate, chlorothalonil, fenitrothion, bromacil, phenthoate and norflurazon, and the rates of degradation were detected by using gas chromatography electron capture detector (GC-ECD). The limit of detection (LOD) was in the range of 0.007~0.105 ppm. The limit of quantification (LOQ) was in the range of 0.024~0.352 ppm, and the recoveries of 9 pesticides were in the range of 71.5~106.5%. The results demonstrated that the ${\gamma}$-irradiation was effective method to remove pesticides such as diuron, dichlorbenil, trifluralin, dimetoate, chlorothalonil, fenitrothion, and norflurazon. However, the bromacil and phenthoate showed lower removal rates in the rate of 40.5 and 54.8%, respectively, at 200 kGy irradiation.

Effects of Feeding Citrus by Products on Nutritional Components of Korean Native Chickens (토종닭 고기의 영양 성분에 미치는 감귤부산물 급여의 영향)

  • Yang, Seung-Ju;Jung, In-Chul;Moon, Yoon-Hee
    • Journal of Life Science
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    • v.18 no.10
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    • pp.1369-1376
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    • 2008
  • In this study, the effects of feeding citrus byproducts on nutritional components of Korean native chickens were investigated. Two samples of Korean native chickens were used for this study: T0 (chickens fed with only feed for laying hen until they became 39 weeks old, not with citrus byproducts) and T1 (chickens fed with citrus byproducts). The feed for T1 was the same as T0 for the first 16 weeks, and then was made by adding 4% of citrus byproducts to the feed for T0 between $17{\sim}39$ weeks. The chicken used for the experiment was obtained by chilling them for 2 days after slaughter. There was no significant difference between T0 and T1 regardless of feeding citrus byproducts, in terms of their breast/thigh's calorie, contents of moisture, protein, fat and ash, total structural amino acid, total free amino acid and composition of saturated/unsaturated fatty acids. The breast's cholesterol amount of T0 and T1 were 48.4 mg/100 g and 47.6 mg/100 g, respectively, while that of thigh for T0 and T1 were 75.7 mg/100 g and 72.8 mg/100 g, respectively, which implies that T1 showed lower amount of cholesterol than T0. T1 showed significantly higher amount of phosphorus, potassium, magnesium and vitamin B2 for thigh than T0 (p<0.05).

Flavonoids and Functional Properties of Germinated Citron (Citrus junos Sieb. ex TANAKA) Shoots

  • Choi, In-Wook;Choi, So-Yun;Ji, Joong-Ryung
    • Food Science and Biotechnology
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    • v.18 no.5
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    • pp.1224-1229
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    • 2009
  • The main objective of this study was to investigate possible application of citron (Citrus junos Sieb. ex TANAKA) seeds, which are massively produced as by-products during citron tea process, into functional food materials. First of all, citron seeds were germinated and produced citron shoots were examined for their functional properties. When contents of flavonoids in citron seeds and their germinated shoots were compared, naringenin, neohesperitin, and hesperitin were remarkably increased in shoots after germination while naringin and didymin were decreased. Concentrations of limonin and nomilin were decreased by germination otherwise their unidentified derivatives were newly formed. A methanol extract of citron shoot had lower $IC_{50}$ values [0.13 and 0.07 mg/mL for 2,2-diphenyl-1-picryl-hydrazyl (DPPH) and ABTS, respectively] than citron seed extract in radical scavenging activities. Addition of 500 mg/mL of citron shoot extract suppressed fat accumulation in 3T3-L1 adipocytes by 36.9%. Oral administration of olive oil along with citron shoot extract (33 mg/kg body weight) to Sprague Dawley rats effectively inhibited absorption of lipid into a body by decreasing blood triglyceride levels from 105.1 to 74.9 mg/dL 2 hr after olive oil administration. According to these results, citron shoot extract as a rich source of flavonoids can be utilized for functional food ingredients with effective antioxidant and anti-adipogenic properties.