• Journal of Biosystems Engineering
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• 제31권6호
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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.

• 한국식품저장유통학회지
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• 제5권4호
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• pp.346-349
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• 1998

개체당 중량과 과육부의 중량은 천일건조한 것이 2.8$\pm$0.03g/ea로 다른 건조방법에 비해 낮았다. 수분함량도 역시 천일건조한 것이 열풍건조를 비롯한 다른 방법에 비해 낮았다. 수분재흡수율은 열풍건조한 것이 다른 건조방법에 비해 높았으며 천일건조한 것이 가장 낮았다. 건조대추의 경도는 천일건조한 것이 8.6$\times$106dyne/$\textrm{cm}^2$으로 다른 건조방법에 비해 월등히 높았다. 부패율은 천일건조대추는 15.3%로 다른 건조방법에 비해 매우 높았고, 갈변도는 천일건조와 천일ㆍ열풍건조를 병행하여 건조한 대추에서 각각 286.5와 196.4%로 다른 건조방법에 비해 월등히 높았다. 탄수화물, 단백질, 지질의 함량은 모든 구에서 유사한 경향을 보였고, 회분의 함량은 천일건조 대추가 다른 건조방법에 비해 높았다. Vitamin C의 함량은 천일건조한 대추가 다른 건조방법에 의해 건조된 대추에 비해 낮았다.

• Journal of Biosystems Engineering
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• 제27권4호
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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.

• 한국식품영양과학회지
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• 제26권5호
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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.

• 한국식품영양학회지
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• 제31권5호
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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.

• 농업과학연구
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• 제45권3호
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• pp.365-378
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• 2018

Anthracnose caused by Colletotrichum gloeosporioides, which is one of the major diseases of red dates, causes severe damages in jujube (Zizyphus jujuba Miller) production in Korea. This study was done to evaluate the inhibition of anthracnose occurrence and pathogen growth by the treatment of environment-friendly materials such as a Bordeaux mixture and loess-sulfur mixture and by defense-response signaling in jujube. The in vitro test of the environment-friendly materials and signaling molecules that were routinely applied did not exhibit any antifungal activities against the pathogen for jujube anthracnose. The Bordeaux mixture and loess-sulfur mixture at a two-fold concentration showed inhibition zones that were 16.0 and 20.3 mm in diameter, respectively. In the pathogen inoculation test with detached jujube tree leaves, while treatment with the environment-friendly materials diluted by half showed no inhibition of lesion development, they did show inhibition of lesion development when they were routinely applied to the leaves. In detached jujube fruits inoculated with the pathogen, better suppressive effects by the treatment of the environment-friendly materials were seen in the fruits at a young stage rather than in the ripening stage. The in vivo test with jujube trees in pots showed that the treatment of salicylic acid (1 mM) resulted in the best suppressive effects against lesion development. The results suggest that it is possible to manage the incidence of anthracnose by the treatment of environment-friendly materials such as the Bordeaux and loess-sulfur mixtures and signaling chemicals such as ethephon, hydrogen peroxide, methyl jasmonate, and salicylic acid in jujube trees and fruits. Consequently, these findings suggest that environment-friendly materials and defense response signaling molecules could be used as suitable candidates for sustainable agrochemicals to manage anthracnose in jujube production.

• 한국식품저장유통학회지
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• 제2권1호
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• pp.185-193
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• 1995

This paper was investigated the changes of the cell wall components, enzyme activities during ripening of jujuba fruits for elucidating the softening metabolism of jujuba fruits. Firmness were decreased during ripening. Moisture content did not show any notable cahanges until ripening stage but they decreased a little In overripe jujuba fruits. Polygalacturonase activities were not detected at nature green stage and $\beta$-galactosidase activities were until turning stage. But polygalacturonase activities in ripening and overripening were 51.31 and 100.72 units/100g-fr, wt. respectively. $\beta$-galactosidase activities were 16.05 and 182.55units/100g-fr. wt. in the same stages. The content of water-soluble protein was increased in overripening. Stage the contents of cell wall and alcohol-insoluble material were. decraesed during maturation, but water-soluble material was increased. The pectin and alkali-soluble hemicellulose were increased until ripening stage, but decreased in overripe jujube fruits. The total pectin and insoluble pectin during ripening, but decreased in overripe jujuba fruits.

• 한국토양비료학회지
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• 제46권6호
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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.

• 한국식품저장유통학회지
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• 제17권5호
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• pp.712-719
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• 2010

본 연구는 한방 약용자원으로 사용되고 있는 대추의 효능과 생리활성에 대한 연구의 일환으로 대추 열매의 열수 및 에탄올 추출물의 폴리페놀 화합물과 각 추출물의 항산화활성을 측정하였다. 대추 추출물의 수율은 미숙 대추가 가장 낮은 11% 내외의 수율을 보였으며, 완숙 대추가 미숙 대추보다 2배 이상 높은 수율을 보였고, 건조 대추의 열수 및 에탄올 추출물은 각각 55.67, 65.95%이었다. 대추 추출물의 폴리페놀 함량은 열수와 에탄올 추출물 모두 미숙 대추에서 가장 높았다. 전자공여능은 추출물의 농도가 증가함에 따라 높았고, 10.0 mg/mL의 농도에서는 천연 항산화제인 ascorbic acid와 같이 90% 이상의 전자공여능을 보였다. SOD 유사활성능은 농도가 높아질수록 증가 하였으나, 미숙 대추의 열수 추출물에서 다른 추출물에 비해 높은 SOD 유사활성능을 나타내었다. 에탄올 추출물의 SOD 유사활성능은 미숙 대추 추출물의 10 mg/mL의 농도에서는 39.92%의 SOD 유사활성능을 확인되었다. 대추 추출물의 아질산염 소거능은 pH 1.2와 추출물의 1.0 mg/mL의 농도에서 50% 이상의 소거능을 보였으며, 미숙 대추 추출물에서 가장 높았다. Xanthine oxidase 저해 활성은 미숙 대추의 추출물에서 높았으며, 추출물의 농도가 증가할수록 증가하였다. 이상의 결과에서 실험에 사용한 시료인 미숙 대추, 완숙대추, 건조 대추에는 항산화 물질의 대표적인 폴리페놀 물질도 다량 함유하고 있을 뿐만 아니라 대추의 열수 및 에탄올 추출물로서 항산화성도 우수한 것으로 보여 천연항산화제나 기능성 식품 및 다양한 식품개발에 응용될 수 있을 것으로 생각된다.

• 한국식품저장유통학회지
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• 제17권1호
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• pp.42-49
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• 2010

본 연구는 대추의 과실 모양을 그대로 유지하면서 기호성이 우수한 제품을 만들기 위하여 우리나라 전통식품의 한 종류인 정과를 접목하고 여러 가지의 전처리 과정을 달리한 대추정과를 제조하고 대추정과의 제조과정 및 최종 제품의 품질특성에 대하여 연구하고자 하였다. 대추정과 제조시 중량의 변화는 당조림공정에서 증가를 보였고, 색도는 당조림공정 후 외부의 명도 L 값은 크게 변화를 보이지 않았지만 적색도(a)과 황색도(b)는 크게 낮아졌다. 수분함량은 건대추(DJF)가 35.06%, 추가건조한 대추(DDJF)가 35.93%였으며, 삼투건조대추(ODJF)가 가장 높은 40.42%를 나타내었다. 20분간 당조림공정을 거친 시료는 예비건조 공정에 비해 2~10% 정도의 수분함량이 증가하였다. 재흡수율은 일반건조대추인 DJF가 119.66%로 가장 낮았으며, 삼투건조 처리한 대추(ODJF)가 가장 높은 124.81%로 나타났다. 물성은 건조방법을 달리한 첫 번째 공정 후에 추가건조대추(DDJF)는 건대추(DJF)에 비해 강도는 3배 이상, 경도는 2배 이상 높게 나타났다. 당조림 공정 후의 물성은 시료간 큰 차이는 없었다. 최종 완성된 정과의 물성도 큰 차이는 없었으나, 색, 외관윤기, 외관기호도, 향, 전체적인 기호도는 삼투건조대추(ODJF)에서 높은 기호도를 보였다. 완성된 정과에 대한 관능검사는 외관기호도, 향, 씹힘성, 뒷맛 및 전체적인기호도는 추가건조한 대추(DDJF)에서 높은 기호도를 보였다. 따라서 전처리를 달리하여 제조한 정과 즉, 추가건조한대추(DDJF)와 삼투건조대추(ODJF)도 대추정과로서의 관능적인 면에서 우수함을 알 수 있었다. 따라서 추가건조한대추(DDJF)와 삼투건조대추(ODJF)도 대추정과로서의 높은 기호성을 보여 좋은 식품이 될 수 있을 것으로 판단되며, 훌륭한 전통식품의 한 종류가 될 수 있을 것으로 생각한다.