• The Plant Pathology Journal
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• v.37 no.3
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• pp.268-279
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• 2021

Citrus scab, caused by the fungal pathogen Elsinoë fawcettii, is one of the most important fungal diseases affecting Citrus spp. Citrus scab affects young tissues, including the leaves, twigs, and fruits, and produces severe fruit blemishes that reduce the market value of fresh fruits. To study the molecular responses of satsuma mandarin (C. unshiu) to E. fawcettii, plant hormone-related gene expression was analyzed in response to host-compatible (SM16-1) and host-incompatible (DAR70024) isolates. In the early phase of infection by E. fawcettii, jasmonic acid- and salicylic acid-related gene expression was induced in response to infection with the compatible isolate. However, as symptoms advanced during the late phase of the infection, the jasmonic acid- and salicylic acid-related gene expression was downregulated. The gene expression patterns were compared between compatible and incompatible interactions. As scabs were accompanied by altered tissue growth surrounding the infection site, we conducted gibberellic acid- and abscisic acid-related gene expression analysis and assessed the content of these acids during scab symptom development. Our results showed that gibberellic and abscisic acid-related gene expression and hormonal changes were reduced and induced in response to the infection, respectively. Accordingly, we propose that jasmonic and salicylic acids play a role in the early response to citrus scab, whereas gibberellic and abscisic acids participate in symptom development.

• Applied Biological Chemistry
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• v.15 no.2
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• pp.175-180
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• 1972

The chemical composition of amino acids in the rind and fresh of Citrus Junos Sieb was studied and compared with that of Citrus natsudaidai Hayate. The results were summarized as follows. 1. Beth of them contained twenty kinds of amino acids, including three kinds of unknown amino acids. 2. Proline in the rind of Citrus Junos and aspartic acid in the rind of Citrus natsudaidai were the richest of all amino acids but on the contrary. Histidine was the poorest of all amino acids in the rind of them. The content of proline amounted to 16.48 mg/100mg in the rind of Citrus Junos and the content of aspartic acid amounted to 32.18 mg/100mg in the rind of Citrus natsudaidai. 3. Aspartic acid was the richest of all amino acids in the flesh of Citrus Junos and the content of it amounted to 32.68mg/100mg. On the other hand, Proline was the richest of all amino acids in the flesh of Citrus natsudaidai and the content of it amounted to 20.93mg/100mg. But the content of histidine as 1.32 mg/100 mg in the flesh of former and tyrosine as 1.18 mg/100 mg in the flesh of latter were relatively small. 4. In the fruits of Citrus Junos and Citrus natsudaidai, aspartic acid and Proline were rich and histidine was poor in quantity. Generally, Flesh contained more amounts of all kinds of amino acids than those rind and especially glutamic acid was richer, compared with other amino acids in flesh.

• Food Science and Preservation
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• v.14 no.4
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• pp.351-355
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• 2007

Solvent-extracted volatile components from dry powder prepared from Citrus unshiu products such as immature Citrus unshiu (PCU), mature Citrus unshiu (MCU), Citrus unshiu peel (CUP), and citrus juice processing wastes (CJPW), were examined. Also, solvent-extracted volatile components from mushroom mycelia of Pycnoporus coccineus (PC), Lentinus edodes (LE), Pleurotus eryngii (PE), Hericium coralloides (HC), Panellus serotinus (PS), and Ganoderma lucidum(GL), all cultivated using citrus pulp solid media, were assayed. Twenty-nine volatile components were identified in dry powder prepared Citrus unshiu and 18 volatile components were characterized from mushroom mycelia. Of these, ${\beta}-elemene$, germacrene-D, and ${\delta}-cadinene$, were derived from CJPW, but caryophyllene, hexadecanoic acid, decanoic acid, and tetradecanoic acid were synthesized by mushroom mycelia.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.541-545
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• 1995

Physicochemical properties and chemical compositions of Citrus fruits produced in Cheju were investigated. Soluble solids, total sugar and acid content of Citrus unshiu were $10.4{\sim}11.0^{\circ},\;8.24{\sim}8.79%\;and\;1.04{\sim}1.20%$, respectively. Vitamin C ranging from $41.19{\sim}46.55\;mg/100\;g$ was higher on medium type than on early type of Citrus unshiu. In case of inorganic elements in Citrus unshiu, potassium content was the highest, in the range of $108.66{\sim}132.65\;mg/100\;g$, and it was higher on C. platymamma than on Citrus unshiu. however, the kinds and contents of carbohydrate in citrus juice were somewhat different among citrus varieties. Sucrose was $46.8{\sim}64.6%$ and others were glucose and fructose, $18.4{\sim}26.9%\;and\;15.2{\sim}30.2%$, respectively. Citric acid content was $75.7{\sim}96.2%$, and others were malic acid, oxalic acid, and fumaric acid in the decreasing order.

• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.309-318
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• 2007

The effects of supplementation of organic citrus on the quality of rice straw silage was investigated in this study. The aim of the study was to improve the quality of rice straw silage using agricultural by-products and therefore to secure the good quality forage sources. Firstly, looking at chemical composition of citrus added rice straw silage, crude protein content appeared improved with the addition of citrus to rice straw silage compared to control while NDF and ADF contents decreased. pH of the silages were different between control(4.39) and treatments$(3.47\sim3.53)$. Lactic acid content was higher in citrus added silage(4.87mM) than in control (3.65mM). External quality of the silages was also better in citrus added silage when citrus added at the equal ratio with rice straw(1 : 1). This trend was the same as with pH and lactic acid content. Propionate was significantly higher in citrus addd silage but butyrate was significantly lower. DM and NDF disappearance rates in the rumen were highest when citrus added at the equal ratio with rice straw(1:1). In conclusion, supplementation of citrus to rice straw silage with equal ratio contributed the best to the improvement of the quality of silage and it may have been due mainly to abundant content of non-structural carbohydrate in citrus.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.875-881
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• 2001

For beverage using Citrus reticulata, Ostrea gigas and medicinal herbs were formulated by determining optimum ratio of mixing to several other ingredients, the results of element and amino acid analyses with Ostrea gigas and Citrus reticulata were as follow. The mineral contents of Ca and Na in Ostrea gigas were 18.8 ppm and highest as 23.8 ppm, respectively. The content of aspartic acid in Citrus reticulata was 14290.431 pmol, and 8 kinds of essential amino acid contained. In the sensory test of beverage using Citrus reticulata, Ostrea gigas, the sensory score(color, taste, flavor) were the best on mixing ratio of Citrus 1g, Amomum 0.25g, Pueraria 0.5g, Ostrea I2g, citric acid 1g, sodium benzoate 0.5g, aspartic acid 0.5g, raw sugar 90g. The general analyses were similar 3 kinds of sample.

• Korean journal of food and cookery science
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• v.31 no.1
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• pp.1-8
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• 2015

Organic acids are known as natural sanitizers. We examined the sanitizing effects of five organic acids (acetic acid, propionic acid, citric acid, malic acid, and lactic acid) and their persistence on three pectinolytic yeast strains isolated from decayed citrus, and the persistence of their sanitizing effects was determined during storage at $4^{\circ}C$ and $16^{\circ}C$. The 7~8 log CFU/mL of the mixed three yeast mixture was exposed to various concentrations of each organic acid for 1 min. The yeast mixtures decreased under detection limit(1 log CFU/mL) in 1% of acetic acid, followed by in 3% of propionic acid with the reduction of 5 log CFU/mL. The citric acid, malic acid, and lactic acid decreased the number of yeasts under detection limit at 7.5%. When treated with deionized water and 1~5% of organic acids were treated on the surfaces of citrus contaminated by yeasts, total numbers of the yeasts decreased under detection limit(3 log CFU) at 5% of acetic acid and 4 log CFU/piece at 5% propionic acid compared with deionized water. When treated with acetic acid and propionic acid on the stem ends of the contaminated citrus, total numbers of the yeasts significantly decreased 0.5 log CFU/piece at 3% of both organic acids. During storage at $4^{\circ}C$ and $16^{\circ}C$ for 20 days, total number of yeasts significantly decreased at 2% acetic acid compared with deionized water. This study suggested that organic acids could be used to sanitize microbial contaminants from citrus for storage and transportation.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.306-312
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• 1998

Free sugar, organic acid, naringin, hesperidin and inorganic elements change of six varities of Cheju citrus fruits; Citrus natsudaidai, C. grandis, C. platymamma., C. sudachi, C. aurantiun and C. unshiu Marc. var. miyagawa by harvest date were investigated. Changes in free sugar of citrus fruits on the different harvesting stages and varieties showed a little differencies. The content of sucrose, glucose and maltose in citrus juice were $44.9{\sim}66.0%,\;15.7{\sim}25.7%\;and\;17.5{\sim}30.1%$, respectively. As the fruits were matured, free sugar was increased, but organic acid was decreased gradually. The major organic acids from the fruit juice were citric acid, malic acid and oxalic acid. Citric acid content exceeded 90%, oxalic acid ranged less than 3.58% and malic acid ranged $0.98{\sim}9.45%$ in total organic acids. Both naringin and hesperidin content showed markedly high in immature fruits, and in rind compare to fruit juice. Naringin and hesperidin content decreased as peel coloration progressed. It was estimated that fully matured fruits would be useful for making processed products, which lead to less turbity and less bitterness.

• Food Science and Preservation
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• v.2 no.1
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• pp.139-146
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• 1995

Soluble solids and total carbohydrates of Citrus miyakawa wase harvested middle of November 1993 Topyung-Dong, Seogwipo-si, and Cheju were 10.7 and 8.57%, and carbohydrate was consisted of about 1/2 sucrose, 1/4 glucose and 1/4 fructose, respectively. Acid content of citrus Juice was 1.04%, and citric acid was 74.27% of total organic acids. Fruit weight, peel thickness, soluble solids, pH, hardness and edible part ratio had a good correlation in linear function with increasing fruit size. Total carbohydrate, reducing sugar and vitamin C of citrus jam made on optimum conditions were 65.33%, 27.98%, and 51.40mg/100g , respectively. Microbial growth on the products were not recognized at 3$0^{\circ}C$ for a month. Compared with other related citrus jellying products, the test sample was excellent in appear ance, taste and total preference degree on sensory evaluation.

• Food Science and Preservation
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• v.3 no.1
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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.