• Food Science and Preservation
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• v.23 no.1
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• pp.127-130
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• 2016

The appearance and physicochemical characteristics of a native jujube (called Yak jujube) and Bokjo jujube were compared in this study. Our results revealed that the native jujube had smaller size, lower hardness, and higher contents of sugar, crude protein, crude fat, crude ash, dietary fiber, and calcium contents, when compared to that of Bokjo jujube. Therefore, native jujube is softer and sweeter, with higher general nutrient content, despite being smaller than that of Bokjo jujube.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.396-402
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• 2015

This study identified a new male-sterile germplasm of Chinese jujube, named male-sterile No. 2 (JMS2), and achieved controlled hybridization using that germplasm as the female parent. The anthers of JMS2 before flower bud opening became shrunken, dingy yellow and much smaller than normal ones, and they changed to brown after anthesis. No pollen was observed in anthers of JMS2 and its male-sterile trait remained stable over different years. A total of 1,642 fruits were obtained from ten intra- and interspecific cross combinations via controlled hybridization from 2008 to 2012 using JMS2 as the female parent. Of those, 27.3% produced seeds, on average (0-72.6%). The rate of fruit with seed (RFS) was significantly different between cross combinations or years. Compared to other cross combinations, the RFS in the combination of JMS2 ${\times}$ 'Xingguang' (a Chinese jujube cultivar with high resistance to jujube witches' broom disease) and JMS2 ${\times}$ 'Xing16' (a sour jujube genotype) remained high in different years and reached means of 48.7 and 58.1%, respectively. Finally, 150 plantlets were regenerated from immature embryos, and 51 of them were randomly selected and identified to be authentic hybrids using amplified fragment length polymorphism (AFLP) markers. This is the first report of hybrids obtained from a cross between Chinese jujube and sour jujube.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.609-621
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• 2000

The purpose of this study was to investigate the effect of addition of jujube on lnjeulmi in storage. Jujube powder was added to lnjeulmi made from the steamed glutinous rice, glutinous rice flour and brown glutinous rice flour. As a result of the sensory evaluation, the more jujube is added, the stronger sweetness and the more bitterness is shown. The sweetness and bitterness, made from brown glutinous rice, of Deachu-Injeulmi added jujube powder is the highest, and the more jujubes are tasted. Tenderness and moistness of Deachu-Injeulmi is decreased in the order of Deachu-Injeulmi made from glutinous rice, brown glutinous rice, glutinous rice flour, tenderness and moistness is increased with less amount of jujube. Chewiness of Deachu-Injeulmi made brown glutinous rice flour is the highest and Deachu-Injeulmi made from glutinous rice is the most rough. Moisture content is decreased in the order of Daechu-Injeulmi from glutinous rice, glutinous rice flour, brown glutinous rice flour. The reducing sugar content about storage period of Daechu-Injeulmi is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour, and it is dramatically reduced until 48 hours of storage. However, it is increased a little bit after 72 hours. The changes in degree of gelatinization by storage period is that it is rapidly reduced until 24 hours, and it is decreased in the order of glutinous rice, glutinous rice flour, brown glutinous rice flour. That is to say, the more jujube powder is added, the less change there is. Springiness and cohesiveness is decreased during storage. Chewiness and gumminess is higher with more jujube, and it is increased until 24hour of storage period, then it is decreased after 48 hours. Hardness of Daechu-Injeulmi made from glutinous rice flour is the highest and the more jujube is added. Hardness of Daechu-Injeulmi added jujube powder is decreased in the order of Daechu-Injeulmi of 2.5%, 10% and 7.5%. The more jujube is added, the less change of the hardness by the storage period Daechu-Injeulmi is observed, thus the speed of the retrogradation is getting slower.

• Culinary science and hospitality research
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• v.19 no.3
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• pp.259-273
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• 2013

Brown sauce is very frequently used for western meat dishes, and this study aims to develop brown sauce for Asians and Koreans by adding jujube concentrate which has natural sugar and is used in Chinese medicine. The ingredients and sensory characteristics of brown sauce added with jujube concentrate were examined and the results are as follows. First, the moisture content increased with increased amount of jujube concentrate added, while the pH decreased. In the results of the sensory evaluation, the sample added with 5% jujube concentrate had the highest score, and the one added with 9% jujube concentrate had the lowest score in color. In the flavor evaluation, the sample added with 5% jujube concentrate had the highest score, and the one added with 9% jujube concentrate had the lowest score. In overall acceptability, the sample added with 5% jujube concentrate had the highest score, and the scores were high in order of 3%, 7%, and 9% concentrates when the samples were heated for 16 hours. Also, when making brown sauce made with beef leg bones, their ingredients continued to flow out even heated for more than 10 hours. Therefore, it was considered that more delicious and healthier sauce could be made by adding jujubes when making beef leg bone brown sauce. Based on these results, even though brown sauce originated from western foods, it can be used to Koreans' taste by adding Korean ingredients. Moreover, more recipes can be made from the brown sauce added with jujube concentrate for more Asians including Koreans to enjoy.

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

• Culinary science and hospitality research
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• v.16 no.5
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• pp.264-276
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• 2010

The purpose of this study is to examine the possible use of functionally elevated Gochujang, a Korean traditional fermented sauce, and the result is as follows. The water content of Gochujang became significantly higher as jujube concentrate was added. The more amount of jujube powder, the less water content of Gochujang. And the water content of jujube concentrate added Gochujang was higher than jujube powder added Gochujang. For the chromaticity, lightness and yellowness were increased while redness and salinity were decreased with more jujube added. The viscosity of jujube concentrate was decreased when its amount was increased, and the viscosity of jujube powder was increased when its amount was increased The results of sensory tests figured out GJC30(30% of jujube concentrate added) and GJP15(15% of jujube powder added) showed the highest preference, so those seem like the best additional level for elevating the sensory value and instrumental quality characteristics of Gochujang. This study showed that the possibility of using functionally fortified Gochujang by adding jujube which is nutritious and rich of health ingredients.

• Food Science and Preservation
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• v.19 no.6
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• pp.901-908
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• 2012

This study was conducted to analyze the antioxidant activities of fermented black jujube and to compare these with those of dried jujube, for the development of functional materials. The antioxidative activities of dried jujube and fermented black jujube extracts were analyzed by electron-donating ability (EDA) using 1,1-diphenyl-2-picryl hydrazyl (DPPH), superoxide-dismutase-(SOD)-like activity by pyrogallol, nitrite-scavenging ability, and xanthin oxidase. The yield of the fermented black jujube extracts was higher than that of the dried jujube extracts, and that of the ethanol extracts was higher than that of the hot-water extracts. The total phenol contents of the hot-water extracts from fermented black jujube were higher. The EDA values of the hot-water and ethanol extracts from fermented black jujube and dried jujube increased with an increase in extract concentration, and were about 85% in a $1000{\mu}g/mL$ extract concentration. The SOD-like activity increased with an increase in extract concentration. The SOD-like activity of the hot-water extract from fermented black jujube was higher than that of the other extracts. The nitrite-scavenging ability at pH 1.2 of the hot-water extracts from dried jujube was higher than that of the other extracts. The xanthine oxidase inhibitory activities of the hot-water and ethanol extracts from fermented black jujube were higher than those of the other extracts, and increased along with the concentrations of the extracts.

• Journal of Distribution Science
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• v.8 no.4
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• pp.25-34
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• 2010

While jujubes are mainly sold in dried forms as wholesome foods, sacrificial food and so on, processed foods from jujube are neither highly recognized nor in high demand. Hence, this study has proposed ways to enhance the demand for jujube processed foods and will help prepare the ground for efficient marketing strategies, based on the survey result on the pattern in which customers in Korea purchase jujube-processed foods. The conclusion for this study has been derived by researching the relevant literature and analyzing the relevant company data and customer survey results. The study implies the following points regarding enhancing the demand for jujube-processed foods. First, long-term solutions are necessary. These may include establishing a technological system that can produce various foods processed from jujubes, and improving the customer accessibility in accordance with the changes in the retail environment. To implement these solutions, it is necessary to familiarize the customers with jujube-processed foods by securing a good sales network and through active promotion and advertising. Second, systematic marketing strategies are needed, which may be applied in developing the products as well as distribution and promotion methods and prices that correspond with the changes in the customer environment and the different tastes for various age, gender and residential area groups.

• Food Science and Preservation
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• v.24 no.4
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• pp.505-509
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• 2017

Water vapor adsorption kinetics of vacuum-dried jujube powder were investigated in temperature and relative humidity ranges of 10 to $40^{\circ}C$ and 32 to 75%, respectively. Water vapor was initially adsorbed rapidly and then reached equilibrium condition slowly. Reaction rate constant for water vapor adsorption of vacuum-dried jujube powder increased with an increase in temperature. The temperature dependency of water activity followed the Clausius-Clapeyron equation. The net isosteric heat of sorption increased with an increase in water activity. Good straight lines were obtained with plotting of $1/(m-m_0)$ vs. 1/t. It was found that water vapor adsorption kinetics of vacuum-dried jujube powder was accurately described by a simple empirical model, and temperature dependency of the reaction rate constant followed the Arrhenius-type equation. The activation energy ranged from 50.90 to 56.00 kJ/mol depending on relative humidity. Arrhenius kinetic parameters ($E_a$ and $k_0$) for water vapor adsorption by vacuum-dried jujube powder showed an effect between the parameters with the isokinetic temperature of 302.51 K. The information on water vapor adsorption kinetics of vacuum-dried jujube powder can be used to establish the optimum condition for storage and processing of jujube.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.590-596
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• 2005

Effects of jujube extract on physicochemical properties of dough were evaluated. Moisture, protein, and ash contents of jujube extract were 92.5, 0.5, and 0.37%, respectively at pH 4.65. Sucrose content was the highest (4,340 mg%) among free sugars of jujube extract, followed by glucose and fructose. Absorption rate increased as observed through farinogram with increasing amount of jujube extract added. Dough development time and stability decreased, whereas degree of weakness increased. Degree of extension decreased as shown in extensograph with increasing content of jujube extract, whereas degree of resistance and resistance/extensibility increased. Amylogram showed, when amount of jujube extract increased, no difference in gelatinization temperature, whereas peak viscosity decreased.