• The Korean Journal of Food And Nutrition
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• v.31 no.5
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• pp.696-702
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• 2018

This study investigated the quality characteristics of jujube wines produced from various fruits (Campbell Early, aronia, apply). Before the preparation of jujube wine, jujube juice was extracted using hot water ($100^{\circ}C$, 2 hr). Different blends of jujube wines were produced by blending jujube juice with various fruits using Saccharomyces cerevisiae. After 18 days of fermentation, the alcohol content of jujube wines ranged between 11.5~12.7%. The pH of the wine ranged from 3.31 to 3.53 and the total acid content from 0.47 to 0.68%. The hue value of jujube wines ranged from 0.88 to 2.21 and the color intensity ranged from 0.93 to 6.29. The brightness of jujube wines ranged from 32.35 to 92.47, the redness from 0.85 to 59.05, and the yellowness from 17.35 to 51.02. By combining aronia with jujube juice, a significant increase in the total polyphenol content and the antioxidant activity (the DPPH radical scavenging activity) of the wine was observed. The total polyphenol content (401.77 mg%) and the antioxidant activity (76.29%) were the highest in the jujube wine blended with aronia. The total anthocyanin content of jujube wines ranged from 81.66 to 135.98 mg% and the tannic acid content from 42.48 to 316.36 mg%. Based on the results of the present study, we suggest that jujube wine produced by blending jujube juice with aronia had excellent quality as well as quality characteristics of the wine.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.5
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• pp.512-520
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• 2017

This study was carried out to develop concentrate of residual jujube flesh around the seed as a thickening agent of Bulgogi sauce. Quality characteristics and sensory test of Bulgogi sauces added with jujube concentrate (30%, 35%, 40%, 45%, 50%) were evaluated in comparison with control sauce containing xanthan gum as a thickening agent. Moisture content of Bulgogi sauce added with 30% jujube concentrate was the highest (74.59%). As content of jujube concentrate increased, moisture contents in Bulgogi sauces significantly decreased. Sugar content of control sauce ($30.82^{\circ}Bx$), was lowest among the sauces. As content of jujube concentrate increased, Sugar content of sauces significantly increased ($33.00{\sim}34.38^{\circ}Bx$). Salinity (%) was highest in control sauce (1.38%), and there was no difference in salinity among the sauces depending on the amount of jujube concentrate. Viscosity was highest in sauce added with 50% jujube concentrate (43.33 cP) and lowest in sauce with 30% jujube concentrate (13.20 cP). As content of jujube concentrate increased, viscosity tended to increase significantly. Spreadability was highest in sauce added with 30% jujube concentrate (8.88 cm). As the amount of jujube concentrate increased, spreadability of sauce tended to decrease significantly. Color value was different according to the contents of jujube concentrate in sauces. L-, a-, and b-values of control sauce were highest at 40.19, 1.5, and 24.57, respectively. The results of the sensory test for Bulgogi sauce showed that overall preference was significantly highest in sauce added with 35% jujube concentrate. Moreover, sauce added with 35% jujube concentrate was preferred the most in terms of appearance, taste, and fluidity. Meanwhile, the results of the differentiation test showed a significant difference in color intensity, jujube flavor and taste, sweet taste, and salty taste. However, no significant difference was observed in fluidity. The results of the preference test for Bulgogi seasoned with sauces added with jujube concentrate showed that overall preference and flavor, taste, and texture preference were highest in Bulgogi seasoned with sauce added with 35% jujube concentrate. However, no significant difference was observed in preference towards appearance among the samples.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.452-457
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• 2013

To obtain the useful data related to optimum nutrient management technique for pesticides-free jujube cultivation, nutrient contents of jujube leaves and fruits and the selected chemical properties of jujube orchard soils were investigated at 9 different orchards with pesticides-free cultivation in Boeun, Chungbuk, Korea. Soil and jujube leaf samples were collected from the different orchards in July and October, and jujube fruit samples were taken in October, 2012. Soil available $P_2O_5$ contents in the optimum level for jujube cultivation were 11% and 33% of total samples in July and October, respectively, but 56% of total samples was higher than the optimum level in both July and October. Exchangeable K and Ca ion contents were 44% and 67% of total samples, respectively, in both July and October, whereas exchangeable Mg ion content was 100% and 56% of total samples in July and October, respectively. Nutrient contents in jujube leaves were higher than those in fresh fruits. In addition, total nitrate, potassium and magnesium contents in the jujube leaves were higher in the samples collected in July than in October.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.7-11
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• 2002

Hydrothermal extraction from dates was done, and then 3 groups of the date extract liquid group (A), the date puree group (B) and the jujube skin flesh group (C) were prepared. And, the omija extract liquid was added to the 3 groups at respective rates of 3:7, 5:5 and 7:3. Then, total 9 medicated diet sources were prepared by adding cinnamon, the ginger extract liquid, honey and pectin. And their physicochenmical and sensory attributes were examined. Total sugar, free sugar and pH increased in the samples of the 3 groups as the addition amount of the jujube extract increased. In chromaticity of respective samples, the "L" value did not show any difference among the 3 groups, but the "a" value was the highest in the "A"group, and "b"value was the highest in the "B"group. In the date puree group and the jujube skin flesh group, their viscosity increased as the addition amount of the jujube extract increased, but in the jujube extract liquid group, no difference was found in its viscosity. As a result of conducting the discrimination test, it was identified that the as the addition amount of the jujube extract was increased, color and sweet taste were feltto be stronger and our taste was felt to be weaker in all 3 groups. In the jujube puree group and the jujube skin flesh group, as the addition amount of the jujube extract increased, the jujube fragrance was felt to be stronger, but in the jujube extract liquid group, no difference was found in its fragrance. And, no difference was found in brightness and viscosity between samples. As a result of conducting the palatability test, no difference was showed in the appearance, but as for the overall palatability including texture, taste and fragrance, preference increased as the addition amount of the jujube extract increased.

• Applied Biological Chemistry
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• v.40 no.1
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• pp.43-47
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• 1997

The weight ratio of the seed in jujube averaged to 19.1%. The chemical components of dried pitted-jujube were moisture 20.4%, protein 5.3%, fat 1.3%, ash 2.7%, fiber 4.4% and nitrogen-free extract 65.9%. Alcohol insoluble solid content of dried pitted-jujube was 17.4%, in which ammonium oxalate-soluble pectin was 3.7%, water-soluble pectin 3.0%, hydrochloric acid-soluble pectin 1.0%, and sodium hydroxide-soluble pectin 1.0%. Jujube contained sucrose, glucose and fructose as free sugar. The sugars of dried pitted-jujube was composed of sucrose 48.1%, fructose 18.7%, and glucose 11.3%. Drying experiments of pitted-jujube and unpitted-jujube were carried out. Moisture content and brix of dried pitted-jujube were reached at that of dried unpitted-jujube(11%, 78 brix in 48 hours of dry) in 11 hours of drying. And this means that dried pitted-jujube dried 4 times faster than dried unpitted-jujube. The extracts of dried pitted-jujube and dried unpitted-jujube were examinet according to the amount of water added and the extraction time. The brix of dried pitted-jujube extract for 30 min is similar to that of dried unpitted-jujube extract for 150 min. The brix of the extracts did not increase after 150 min extraction. As to the color of extract, 'L' value was higher in dried unpitted-be, while 'a' and 'b' values were higher in dried pitted-jujube.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.3
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• pp.349-356
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• 2006

This study was carried out to survey the effect of Jujube extract on the growth of 3 strains of lactic acid bacteria(LBA) starter cultures in the MRS broth by the addition of 0, 0.1, 0.5, 1 and 2% extract The pH, titratable acidity and OD of LAB were investigated in order to get fundamental knowledge for the development a new product. The effects of Jujube extract on the growth of LAB were variable depending upon the LAB species and concentrations of Jujube extract significantly (p<0.05). In the results, Jujube extract enhanced the acid production and propagation by the 3 LAB strains with increasing concentration of Jujube extracts until 2.0% added was to the MRS broth medium (p<0.05). Addition of Jujube extract markedly stimulated the acid production and propagation of Lactobacillus acidophilus, Streptococcus thermophilus and Bifidobacterium longum.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.713-719
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• 2010

The objective of this study was to evaluate the quality characteristics of Dasik containing different levels of jujube paste (0%, 60%, 70%, 80%, 90%). Moisture composition of the paste ranged from 19~29% As the content of jujube paste increased, the lightness (L) and yellowness (b) decreased while redness (a) increased In the texture profile analysis, as the content of jujube paste in Dasik content increased, the hardness decreased Cohesiveness and springiness did not show significant differences according to amount of jujube paste. The results of the sensory evaluation show that sweetness, bitterness, and overall acceptability were the highest in Dasik containing 80% level jujube paste.

• Preventive Nutrition and Food Science
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• v.18 no.1
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• pp.50-59
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• 2013

Black jujube was made by aging dried jujube and its physiochemical characteristics, antioxidant activities and ${\alpha}$-glucosidase inhibitory activities were evaluated. The moisture and sugar contents were increased depending on the period of aging times and the pH was reduced thereby increasing acidity. The color of black jujube extract was changed from red to black resulting in decreases of Hunter color values L, a and b. As the aging progressed, sucrose was decomposed by increasing glucose and fructose, indicating higher contents of the total reducing sugars. Among the six different types of organic acids extracted from dried jujube, the levels of oxalic acid and citric acid were increased as the aging progressed. The total polyphenol contents in ethanol and water extracts of dried jujube were 7.74 and 8.12 mg/g, respectively. The water extract of black jujube aged for 48 hr contained the highest polyphenol contents at 16.82 mg/g. The 5'-hydroxymethylfurfural (5'-HMF) contents of black jujube extract significantly increased by longer aging times, and contained higher contents in the ethanol extract than water extract. The ethanol extract of black jujube showed the highest 5'-HMF content with 338.89 mg% after aging for 3 days. Also, $IC_{50}$ values of black jujube aged for 72 hr evaluated by DPPH and ABTS radical assays were 0.54 and 0.59 mg/mL, respectively. ${\alpha}$-Glucosidase inhibitory activities of black jujube at the concentration of 3.33 mg/mL (ethanol extract) increased from 65 to 80 % after aging for 72 hr.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.59-65
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• 2013

The jujube is an important fruit tree species in Korea. Traditionally, classifications of jujube cultivars have been based on morphological characters; however, morphological identification can be problematic because morphological traits are affected by environmental conditions. Therefore, DNA markers are now being used for the rapid and accurate identification of plant species. Inter-simple sequence repeat (I-SSR) is one of the best DNA-based molecular marker techniques, which is useful for studying genetic relations and for the identification of closely related cultivars. In this study, 5 Korean jujube trees and 1 jujube tree imported from China were analyzed for 16 I-SSR primers. Amplification of the genomic DNA of jujube cultivars by using I-SSR analysis generated 100 bands, with an average of 6.25 bands per primer, of which 45 bands (45%) were polymorphic. The number of amplified fragments with I-SSR primers ranged from 2 to 13. The percentage of polymorphism ranged from 10% to 100%. I-SSR finger printing profiles showed that 'Boeun jujube' and 'Daeri jujube' had characteristic DNA patterns, indicating unequivocal cultivar identification at molecular level. According to the results of clustering analysis, the genetic similarity coefficient ranged from 0.68 to 0.92. 'Boeun jujube' and 'Daeri jujube' were divided into independent groups, and 'Bokjo jujube', 'Geumseong jujube', 'Wolchul jujube', and 'Mudeung jujube' were placed in the same group. Therefore, I-SSR markers are suitable for the discrimination of 'Boeun jujube' and 'Daeri jujube' cultivars.

• Journal of Biosystems Engineering
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• v.31 no.6 s.119
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• pp.500-505
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• 2006

Jujube is one of korean most favorite fruits. Harvesting operations of the jujube farming, however, completely depend on hand labor. Especially, collecting operation requires about three times of hand labor compared with separate operation by impacting or shaking of twigs in the hand-harvesting system of jujube fruits. Consequently, jujube farmers sincerely demand the mechanization of the collecting operation of jujube fruits in the harvesting operation. A new collecting system was designed and constructed five parts-collecting pad, guide ring system, sorting system, frame with driving system, and handle with operation levers, which performed collecting operation of jujube fruits without missing fruits in five part functions, however, an extra future more deliberate study would need how to handle conveniently the collecting pad of the prototype in the narrow space of row of the jujube farm.