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

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

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

• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.527-534
• /
• 2011

The purpose of this studies was analyzed moisture content, rheology and sensual test of jujube jungkwa by addition of water, sugar, fructose at processing of jujube jungkwa for development the optimization for processing of jujube jungkwa. The changes of moisture contents at process condition of jujube jungkwa were increased by increasing of sugar and water quantity. And moisture contents of jujube jungkwa were increased by high fructose quantity and low sugar quantity, but were decreased by high sugar and fructose quantity. The 'b' values of jujube jungkwa at low sugar quantity were decreased by the increasing of water quantity, but increased at high sugar quantity. The cohesiveness of jujube jungkwa at 0.03 kg of fructose were high by the increasing of sugar quantity, but those at 0.065 kg of fructose were high by the decreasing of sugar quantity. And those at 0.050 kg of fructose were similar without the quantity of sugar. The sweet taste of jujube jungkwa were increased by the increasing of water and fructose quantity. The characteristics of jungkwa at conditions of processing for the best quality of jujube jungkwa were 18-20% of moisture content, 2.0-3.0 of 'b' values, 3.0-3.2 of color scores, and 3.3-3.4 of sweet taste scores. The conditions of processing for the best quality of jujube jungkwa were determined to 0.95-1.04 L of water, 0.052-0.060 kg of fructose at 0.95 kg of sugar.

• Food Science and Preservation
• /
• v.6 no.1
• /
• pp.61-65
• /
• 1999

This study was carried out to investigate change in the components according to drying methods of jujube. Raw jujube was dried with five methods such as sun-drying, hot-air drying after pretreated with sunlight, blanching, microwave treatment, respectively. The contents of soluble sugar and protein in sun-dried jujube were higher than those of other drying methods. The free sugars of dried jujube were consisted of sucrose, glucose and fructose. And the contents of free sugar was not different by drying methods. The major organic acids of dried jujube were oxalic acid, citric acid and malic acid. The contents of glutamic acid, glycine and alanine were higher than those of other amino acids, and the content of each amino acid was not different by drying methods.

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

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

• Food Science and Preservation
• /
• v.23 no.7
• /
• pp.1004-1011
• /
• 2016

Flavonoids, non-nutrient secondary metabolites of plants, are widely distributed in commonly consumed agro-food resources. Flavonoids include aglycones, and their glycosides are reported to have potential health-promoting compounds. The aim of this study was to investigate flavonoid glycosides in the fruit and leaves of Zizyphus jujuba var. inermis (Bunge) Rehder (jujube). A total of six flavonoids (five flavonols and one chalcone) were identified in jujube fruit and leaves by using ultra-performance liquid chromatography-diode array detector-quadrupole time of flight mass spectrometry along with chemical library and an internal standard. In positive ion mode, six flavonoids were linked to the C- and O-glycosides which were conjugated with sugar moieties based on kaempferol, quercetin, and phloretin aglycones. Total flavonoid contents of leaves (8,356.5 mg/100 g dry weight (DW)) was approximately 900-fold higher than that of fruit (fresh fruit, 13.6 mg/100 g dry DW; sun-dried fruits, 9.2 mg/100 g dry DW). Quercetin 3-O-rutinoside (rutin) and quercetin 3-O-robinobioside were the predominant flavonols in fruit and leaves of jujube. In particular, rutin had the highest content (6,735.2 mg/100 g DW) in leaves, and rutin is a widely reported bioactive compound. Phloretin 3',5'-di-C-glucoside (chalcone type) was detected only in leaves. The leaves of jujube contain a high content of flavonoids and the results of this study indicate that jujube leaves may be a source of bioactive flavonoids.

• The Korean Journal of Food And Nutrition
• /
• v.23 no.3
• /
• pp.332-341
• /
• 2010

The chemical composition characteristics of jujube wine using different preparation methods including extraction in -soju (25%) and fermentation were investigated. The jujube wine was prepared by soaking in soju using- whole fruit(WJ-S1) or seed-removed fruit(WJ-S2). Fermentations of the jujube wine were started by using whole fruit(WJ-F1), seed-removed fruit(WJ-F2) or extracts of whole fruit(WJ-F3) after adding 24% sucrose. The pH of all samples decreased from a range of 4.92~5.42 at the start time to 3.66~4.97 after 100 days. The treatment WJ-F3 showed the lowest pH among all treatments. Total acid content was 0.67~1.01% at the initial stage and then changed to 0.51~0.88% after 100 days. Total sugar and reducing sugar contents were 1.20~13.8% and 0.50~4.45% at initial stage and then changed to 1.53~4.52% and 1.75~3.82% after 100 days respectively. These sugars decreased during the preparation and fermentation of the jujube wine. The amounts of free sugars including fructose, glucose, and sucrose ranged from 1.53~4.52% and treatment WJ-F3 showed the highest amount(1.95~13.64%) compared the other treatment. Glucose level were high in treatment WJ-S1 and WJ-S2, and fructose was increased in treatments WJ-F1, WJ-F2, and WJ-F3 after 60 days. Amino nitrogen content was 0.02~0.11% after 20 days and 0.07~0.14% after 40 days respectively. Solid content was 2.68~7.76% at the initial fermentation stage and changed to 4.81~9.73% after 100 days. Hunter color(L values) were 88.45~96.74 at the initial stage and then changed to 92.62~100.45 after 100 days. Preference tests a significant difference between the two types (extraction and fermentation) of jujube wine. And treatment WJ-S2 received the highest preference scores among the all treatments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.8
• /
• pp.1296-1302
• /
• 2013

The quality of fresh jujube (Zizyphus jujuba) fruit rapidly declines in the postharvest stage and thus the effective storage conditions for agricultural warehouses were investigated in this study. Fresh jujubes (~10 kg) were stored using five different storage methods: plastic box without further packaging as a control (C-PL), plastic box with hanji packaging (H-PL), plastic box with functional film packaging (F-PL), cardboard box with hanji packaging (H-CB), and cardboard box with functional film packaging (F-CB). The storage boxes were stored in a refrigerator ($0^{\circ}C$ and 80~90% RH), equipped with an ethylene gas scavenging device for 9 weeks and then the quality characteristics were analyzed. The control storage conditions of jujubes showed a substantial decline in quality with decreases in moisture content, hardness, and sugar content as well as increases in decay ratio and redness. Among the tested storage conditions, F-CB was most effective in terms of maintaining the quality of jujube fruit while maintaining firmness, weightlessness, ripening degree from redness and visible appearance. In conclusion, effective storage and packaging conditions during storage enabled maintenance of fruit quality of jujubes for 9 weeks.