• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.314-319
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• 1997

Sugars in Korean jujube fruit and jujube fruit drinks were studied. The sugars in Korean jujube fruit were extracted by boiling with water for 30min and stirring for 1 hour at 7$0^{\circ}C$ after soaking in the water for 24 hours at 4$^{\circ}C$ followed by crushing. Korean jujube fruit was found to contain 25% of sucrose, 21.2% of fructose and 20.7% of glucose. Korean jujube fruit drinks of V company and H company were found sugar composition of 5.9% and 6.9% of sucrose, 2.2% and 2.1% of fructose and 2.4% and 2.4% of glucose, respectively. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. A viscous material in jujube fruit and jujube fruit drinks was separated by ethanol fractionation, and identified as pectin by 1H-NMR and carbazole analysis. Pectin of Korean jujube fruit, jujube drink of V company and jujube drink of H company was found to contain 61, 58 and 55% of galacturonic acid, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.827-830
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• 1997

Sensory evaluation method was used to develop a type jujube tea the organoleptic properties were evaluated with regard to the optimum sugar content, clarity, drinking temperature and fruit pulp content of the jujube tea. Clarified jujube tea extracted from 25% by weight of dry jujube fruits and 75% water was preferred to those from 15%, 20% and 30% jujube fruites although those from 20% and 30% were not significantly different at 5%level. In spite of the average acceptability score of cloudy jujube tea with 5% of added fruit pulp was not significantly different from that of clarified one, the more fruit pulp in the tea products the worse its acceptability. Cold jujube tea was preferred to warm and hot ones, but these were not significantly different.

• Korean Journal of Medicinal Crop Science
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• v.26 no.6
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• pp.477-481
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• 2018

Background: Recently, jujube (Zizyphus jujuba Mill.) has been attracting attention as a fruit, and its cultivation in rain shelter house is increasing to produce the high quality fresh jujube. This study was carried out to investigate the growth and fruit characteristics of jujube according to the types of rain shelter house. Methods and Results: The characteristics of 5-year-old Bokjo cultivar cultivated in 3 types of rain shelter house, multi span rain shelter house with roof vent (Type I), single span house with a column in the center and roof vent (Type II) and single span house with a column in the center and without roof vent (Type III), and open field were examined. The sprouting and blooming period were different among the types of rain shelter house. The diameter of main stem was higher in rain shelter houses than in the open field. There was no a significant difference in fruit number per leaf stem among the types of cultivation. The incidence of fruit cracking in open field cultivation which was 51.2% was much higher than that in Type I 21.6%, Type II 19.3%, and Type III 25.5%. The fruit size and weight in rain shelter houses, especially in Type III rain shelter house were higher than those in the open field and the soluble solids content of fruit in Type I and Type II was higher than in Type III rain shelter house and the open field. Conclusions: The results show that the growth and fruit quality of jujube were improved by cultivation in rain shelter house, and affected by the types of rain shelter house.

• Food Science and Preservation
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• v.17 no.1
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• pp.42-49
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• 2010

This study was developed a multi-step process of functional jungkwa preparation from jujube fruits to prepare a new processed food, and investigated on the quality of jujube jungkwa. The weight of jujube fruits notably increased during the second processing, compared with jungkwa prepared from dried jujube fruits using an osmosis drying treatment. The weight of jungkwa produced in the second processing step was less than those in the first step. The Hunter values (L, a, b) of dried jujube fruits after the first processing were less than those of control jujube fruits. The L value did not change after the second processing of jujube jungkwa, but the a and b values were markedly decreased. However, the Hunter values did not change during the third processing step. The moisture content of dried jujube fruit, and dried fruit treated by supplementary drying (DDJF) was 37.74 and 35.93%, respectively, and that of dried fruit treated by osmosis drying was 40.42%. The moisture content of dried jujube fruit after the second processing decreased by 2-10%, and by 4-10% after the third processing. The reabsorption ratio of jujube jungkwa after the second processing was 16.93%, and that of jungkwa produced from osmosis-dried fruit 24.81%. The strength and hardness of dried jujube fruit treated with supplementary drying (DDJF) were higher, at 3 and 2, respectively, compared to the values of dried jujube fruit. The rheology of jujube fruit and jungkwa did not change during the second processing. The color, glossiness, acceptability of appearance, flavor, and overall acceptability of dried jujube fruit treated by osmosis drying as the second processing step were somewhat higher than those of fruit processed by other methods. The scores for appearance, flavor, chewiness, after taste, and overall acceptability of dried fruits treated with supplementary drying as the third processing step were somewhat greater than those of fruit prepared by other means. Accordingly, we have developed a process for preparation of jungkwa from dried jujube fruit treated by supplementary drying and osmosis drying as the second and third processing steps.

• Korean Journal of Medicinal Crop Science
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• v.25 no.3
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• pp.160-164
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• 2017

Background: This study were performed to determine the effect of root pruning of Zizyphus jujuba var. inermis (Bunge) Rehder. Root cutting inhibit vegetative growth and promote reproductive growth as temporarily reducing growth, net assimilation, water potential of leaf and cytokinin level. Methods and Results: The root pruning was treated of the root cutting widths 50, and 80 ㎝ and the root cutting depths 10, and 20 cm. The amount of root pruning and the number of suckers were the highest in the root-pruning treatment at a width of 50 cm and a depth of 20 cm. The blooming time was from June 18 to 20, and no difference was observed in the blooming time among the root-pruning treatments. The number of flowers was rather higher in the root-pruning treatment at a width of 50 cm and a depth of 20 cm and at a width of 80 cm and a depth of 20 cm. The percentage of fruit setting was higher in the plants whose roots were pruned at a depth of 20 cm than in the untreated plants. The fruit size, fruit weight, and sugar content showed no difference among the root-pruning treatments. Conclusions: The results showed that percentage of fruit setting increased with root pruning, while no difference was observed in the growth and fruit quality of plants.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.455-462
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• 2020

Background: The purpose of this study was to analyze the applicability of dried jujube (Zizypui Fructus) distributed by size as a functional food material and herbal medicine by evaluating its physicochemical characteristics and betulinic acid content. Methods and Results: It was shown that the carbohydrate content of in jujube fruit significantly increased with fruit size; 81.42% for large, 79.83% for medium, and 76.39% for small. Similarly, the dilute ethanol extract content of each group was 72.48% (large), 69.56% (medium), and 64.16% (small). A free sugar analysis indicated that glucose, fructose and sucrose were found in quantitieds proportional to jujube fruit size, the total free sugar values were 68.85%, 63.93%, and 57.37% for large, medium, and small fruit sizes respectively. The betulinic acid content for large, medium, and small fruit was 0.50 mg/g, 0.54 mg/g, and 0.58 mg/g respectively, indicating that smaller jujube contained a higher amount of betulinic acid. Conclusions: It is considered that betulinic acid content could be used as a criteria for jujube fruit quality control.

• Research in Plant Disease
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• v.8 no.1
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• pp.41-44
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• 2002

Two species of Phytophthora were isolated from infected fruits of jujube. Among 18 isolates collected, 6 were identified as P. nicotianae and 12 as P. patmivora on the basis of their mycological characteristics. The former produced no caduceus, ovoid to spherical sporangia in contrast to caduceus, ellipsoid, and broadly avoid to spherical ones of the latter. These two species were shown to be heterothallic and markedly papilate, chlamydospores abundant, and Al mating type. They skewed strong pathogenicity to fruits of jujube and pear while no symptom was produced on apple fruit by artificial inoculation. This is the first report of juiube fruit rot caused by P. ninotianae and P. palmivora in Korea.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.433-437
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• 1997

The jujube alcoholic beverage, one of Korean traditional wine was manufactured by varying the additional levels of jujube fruits from 1.89 to 7.57% on the basis of raw material and the quality of wine was anaylzed by physical, chemical and sensory evaluation. Fermentation temperature of wines Increased to the highest value of $24{\sim}26^{\circ}C$ in the 2nd day of fermentation. Jujube fruits effected the increase in total acid contents. Both reducing and total sugar contents were on the peak values of $13{\sim}53%$ and $43{\sim}51%$ after the 2nd brewing stage$(1{\sim}1.5day) and continuously decreased afterwards. Ethyl alcohol concentrations were rapidly increased In $1{\sim}3days$ of fermentation and their increasing rates were affected with the added amount of jujube. Amylase activity was on the highest value in $2{\sim}2.5{\;}days$ and decreased afterwards. According to the sensory evaluation of the overall quality Dacchusul could be classified into 2 groups. The superior group was composed of E, C, B, D and the inferior group included A and F. However the highest sensory quality was observed from E which was added at the level of 7.57% jujube fruit.

• Journal of Biosystems Engineering
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• v.27 no.4
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• pp.283-292
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• 2002

Mechanical and physical properties of various parts of jujube (Zizyphus jojoba Miller) such as fruits, leaves, secondary branches, and leafy stems were measured and analyzed. The physical dimensions of the fruits were measured using a digital caliper, and the detachment force of the fruit and leafy stems was measured using a force gauge. The physical characteristics of the secondary branches such as the modulus of elasticity and the torsional rigidity were tested using a universal testing machine (UTM). The physical characteristics of leafy stems such as length and weight were also measured using a digital caliper and a digital scale, respectively. The detachment force of leafy stems and the area of the leaf also measured. The terminal velocities of the jujube fruits, leaves, and leafy stems were measured using a custom made terminal velocity experiment system. Diameter of the major and minor axis of the jujube fruit, weight of the fruit, and detachment force of the fruit stem was average of 32.02 mm, 23.92 mm. 10.0 ${\times}$ 10$\^$6/ ㎥, 8.99 g, and 5.43 N. respectively. The detachment forces of the jujube fruits increased and the force-to-weight ratio of the jujube fruits decreased as the weight of the jujube fruits increased. The modulus of elasticity of the secondary branches of the jujube was average of 7.01 ${\times}$ 10$\^$8/ N/㎡ and decreased as diameter of the secondary branches increased. The average torsional rigidity of the secondary jujube branches was 5.2 ${\times}$ 10$\^$-/ N/㎡, and the torsional rigidity decreased as the secondary branch diameter increased. The distribution of the torsional rigidity data associated with the diameter of the branches, however. widely scattered and it was difficult to find any relationship between the diameter of the branches and the torsional rigidity of tile branches. The weight of the leafy stems, number of loaves attached to the leafy stems, diameter of the stem side of the leafy stems, diameter of the leafy stem end was average or 0.7 g, 6.6 ea, 12.2 cm, 4.5 mm, and 2.7 mm, respectively. The major and minor axis of the .jujube loaves, area of leaves, weight of the leaves. and detachment force of the leaves was average of 5.7 cm, 3.3 cm, 12.98 cm$^2$, 0.20 g, and 4.39 N, respectively. The terminal velocity of the .jujube fruits increased as the weight of the fruits increased. The terminal velocity of the leafy stems, however, did not show a relationship with the weight of the leafy stems and the number of leaves attached to the leafy stem. The terminal velocity, however, slightly increased as the length of the leafy stems increased.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.402-407
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• 1998

Phytophthora rot on jujube fruit has occurred at several cultivation areas in Kyung-buk and Kyung-nam provinces. Symptoms consisted of brownish to reddish rot on fruits resulting in early drop or mummification. The causal fungus isolated from infected fruits and adjacent leaf stalks was identified as Phytophthora citricola, which has never been reported in Korea. Sporangia were semi-papillate, noncaducous and highly variable in shapes. Plerotic oospores with paragynous antheridia were abundant is single cultures. Sporangia of two isolates were measured as 38-76$\times$20-40 ${\mu}{\textrm}{m}$ and averaged 51.4$\times$27.0 and 55.6$\times$36.0 ${\mu}{\textrm}{m}$. Oogonia were ranged from 26 to 36 ${\mu}{\textrm}{m}$ and averaged 31.3 and 32.0 ${\mu}{\textrm}{m}$. Colony pattern was slightly radiated with sparse aerial mycelia on common media. Minium, optimum and maximum temperatures for mycelial growth were recorded at 7, 25, and 32$^{\circ}C$, respectively. Among tested media, 10% V8A was the best and $25^{\circ}C$ was better than 15$^{\circ}C$ for oospore formation of the fungus. The jujube isolates of P. citricola were readily differentiated from other closely related species in the genus, namely; P. nicotianae, P. citrophthora, P. cactorum, P. capsici, and P. plalmivora on the basis of PCR-RFLP of r-DNA. The fungus showed strong pathogenicty to jujube, apple, pear, orange, persimmon and eggplant, and relatively weak to citron, tomato, pepper and cucumber. In this study, P. citrocola is firstly identified and jujube fruit rot caused by the fungus is recorded as a new disease in Korea.