• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.217-221
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• 1994

The essential oil of astringent persimmon leaves was extracted by a gas co-distillation method and its effects on Kimchi fermentation were examined. The changes of pH and titratable acidity of Kimchi during fermentation at 15$\circ $C generally decreased by the addition of essential oil of astringent persimmon leaves, and the growth of microorganisms associated with Kimchi fermentation was also inhibited. The fermentation time of Kimchi reaching to the maximum number of cell counts was greatly extended as compared to that of the Kimchi fermented without the addition of essential oil. The greatest antimicrobial activity activity of essential oil of persimmon leaves was shown against Lactobacillus plantarum among varoius bacteria associated with Kimchi fermentation. The antimicrobial activity of essential oil against Saccharomyces cerevisiae was much higher then that against lactic acid bacteria such as L. plantarum.

• Culinary science and hospitality research
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• v.14 no.2
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• pp.273-285
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• 2008

The purpose of this study was to find appropriate processing condition of astringent persimmon and persimmon leaf granular tea. Under the condition of 4 hour extraction and $50^{\circ}brix$, extraction yield and concentrating of astringent persimmon were the greatest. Under the condition of 2 hour extraction and $7^{\circ}brix$, extraction yield and concentrating of persimmon leaf were the greatest. The optimum condition of granular tea with astringent persimmon and persimmon leaf added was the best in astringent persimmon concentrate of 16% and persimmon leaf concentrate of 4%. It had the best taste after the condition in a brix value of 16.15% and a pH of 5.57. The L-value of chromaticity was -79.13, a-value 2.27, and b-value 2.41. In the sensory properties correlation analysis of astringent persimmon and persimmon leaf granular tea, sweet taste, color acceptability, odor acceptability and taste accept-ability were positively significant correlation with most sensory properties. However, astringent taste was no significant correlation with sensory acceptability. Bitter taste and after taste were negatively significant correlation with most sensory properties.

• Food Science and Preservation
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• v.4 no.3
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• pp.323-330
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• 1997

Changes in antioxidative substance levels in eleven different cultivars of persimmon leaves during growth were investigated. In general, the contents of soluble phenols, L-ascorbic acid and flavonoids in astringent persimmon leaves(APL) were higher than those of nonastringent persimmon leaves(NAPL). The soluble phenol contents in APL and NAPL showed a tendency to decrease throughout leaf growth. L-ascorbic acid content in APL decreased rapidly during growth, whereas its content in NAPL reached its highest value at the late of July, and then decreased rapidly. Major flavonoids in APL and NAPL were quercetin and Kaempferol which were present in conjugate forms. Before acid hydrolysis, the contents of kaempferol and quercetin in APL and NAPL remained at a relatively constant level until the late of July, and then decreased slightly. After acid hydrolysis, kaempferol contents in APL and NAPL varied significantly by cultivar and growth stage, while quercetin contents decreased slowly until the late of July, and then increased drastically, reached a maximum at the early of August, afterward continuously decreased. These results suggest that APL harvested at the early of June may be useful as potential sources of natural antioxidants.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.201-205
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• 1982

As a series of study on the removal of astringency and production of tannin substances, this experiment was conducted to investigate changes of tannin contents and microscopic observation on leaves of persimmon(Diospyros kaki L.). Changes of tannin contents of leaves and fruits in Daegu Bansi(astringent variety) were of similar tendency in content of total and soluble tannin during growth. It seemed therefore that tannin contents of leaves in astringent variety were closely concerned with tannin of fruits. But Fuyu(sweet variety) was different from each other during its growth. Histological form of leaves in microscopic observation had similar tendency between astringent and sweet varieties. It was observed that tannin substances were contained in epidermis cells of levels, that tannin substances were transfered in phloems of nerves system, and that tannin cell existed too in the vicinity of nerves system.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.4
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• pp.276-280
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• 2013

D. kaki and D. lotus are used as rootstocks for astringent persimmons in Korea but characteristics of their seedlings have not been determined. In this experiment, their seeds were sown in 3-L pots on April 18 and the seedlings were grown until October 24. Growth and nutrient absorption were compared at the end of the season after destructively harvesting the seedlings. Seedling growth of D. lotus was much faster than that of D. kaki in terms of total stem length, stem diameter, and number of leaves. However, chlorophyll value and specific leaf weight were higher in D. kaki than in D. lotus. Dry weight of D. lotus was 3.6- and 3.7-fold higher than that of D. kaki in above-ground parts and the root, respectively. D. kaki seedlings were characterized by higher concentrations of N, P, K, Ca, and Mg in the leaves, stem, or the root. However, total contents of the elements were 1.8- to 3.7-fold higher in a D. lotus seedling due to its greater dry weight. Since D. lotus seedlings absorbed more inorganic elements on a tree basis and grew more vigorously than D. kaki seedlings, the level of fertilization for astringent persimmons should be adjusted depending on rootstocks to maintain the trees at the optimum vigor.

• Food Science and Preservation
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• v.30 no.6
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• pp.983-990
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• 2023

This study was conducted to develop a preservation technology that can induce changes in physicochemical properties to effectively utilize of persimmon leaves. The application effects of steaming or freezing technique were investigated. Astringent persimmon leaves were steam-blanched (100℃, 30 sec) or frozen (-20℃, 15 d), followed by hot-air drying (50℃). The physicochemical properties of the extract obtained by hot-water leaching from the dried leaves were compared. The extract of leaves dried without pretreatment was used as a control. L* value was higher in steamed than in control and frozen. a* value was highest in the control. The browning index was higher in the frozen and lower in the steamed than in the control. Soluble solids were the highest in the steamed and the lowest in the frozen. Sucrose content was relatively high in the steamed, and the glucose and fructose contents were relatively high in the frozen. Total polyphenol content and DPPH radical scavenging activity were higher in steamed and lower in frozen than in control. Thus, it was confirmed that steam or freeze pretreatment after harvesting persimmon leaves affects the extraction yield, color, antioxidant capacity and component changes of dried persimmon leaves. Unlike steaming, freezing pretreatment showed the effect of promoting decomposition and browning reactions, and it is considered useful when such an effect is needed.

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.255-263
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• 2010

Kojongsi persimmon (Diospyros kaki) is the major cultivar of astringent persimmon in southern of Korea. Kojongsi persimmon leaf has been traditionally used for acute and chronic diseases in Oriental countries. The purpose of this study was undertaken to investigate the antioxidative activities of the extract of Kojongsi persimmon leaf during growth. We investigated the antioxidant effects of the persimmon leaf extracts during growth on total polyphenol, total flavonoid, electronic donating ability (DPPH), nitrite (NO) scavenging and superoxide dismutase (SOD)-like activity. The next, we investigated the possible cell protective effects of the persimmon extract treatment against ultraviolet B (UVB)-induced injury in HaCaT keratinocytes. The contents of total polyphenol and flavonoid in leaf extract of Kojongsi persimmon were increased in time-dependent manner. In Jun, DPPH and NO radical scavenging and SOD-like activities in the leaf extract of Kojongsi persimmon was increased to the highest. However, the antioxidant activities in persimmon varieties were not any difference. The cell cytotoxicity by UVB irradation in HaCaT keratinocytes was significantly increased with the compared to the control group. However, the treatment of leaf extract of Kojongsi persimmon in HaCaT keratinocytes was shown to protective effect against UVB-induced cell cytotoxicity. These results suggest that the leaf extract of Kojongsi persimmon has potent antioxidant activity, and protective effect against UVB-induced keratinocyte injury. Thus, these properties may be contributed in the care of acute and chronic diseases.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.166-170
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• 2013

BACKGROUND: Persimmon growers have often tried various regimens of K fertilization to improve fruit quality. This experiment was conducted to determine the effects of K rates on concentration of inorganic elements in different tree organs and on fruit characteristics. METHODS AND RESULTS: Six-year-old non-astringent 'Fuyu' persimmons, grown in 50-L pots, were used. Total K amounts of 0 (no-application), 12, 25, 37, and 66 g were fertigated to a pot with KCl solution at 3-to 4-day intervals from July to September. The 0 K trees received no K fertilizer for the two previous years. Leaves, fruits, and shoots were sampled in November. K concentrations in leaves and shoots increased significantly by increasing K rate; leaf K, 0.49% for the 0 K, increased to 3.09% for the 37 g and 3.11% for the 66 g trees. Fruit K was notably lower for the 0 K, but there were no significant differences among the trees as long as they were supplied with more than 12-g K. In the trees with 0 K, leaf necrosis in the margin was apparent in June and the symptom progressed toward the midrib. Some leaves scorch-rolled from the margin in August. The greatest effect of K rates was on fruit size; it significantly increased to 181 g for the 12 g, 203 g for the 37 g, and 206 g for the 66 g compared with 150 g for the 0 K trees. However, K rates did not affect firmness and soluble solids of the fruits. The fruits of the 0 K trees were characterized by better coloration. CONCLUSION(S): The K-rate effect on inorganic elements depended on tree organs and fruit size was the major parameter to be affected by the K rates.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.59-66
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• 2006

The damaged area by and the distribution of Japanese gall forming thrips, Ponticulothrips diospyrosi Haga et Okajima (Thysanoptera: Phlaeothripidae) in Korea were surveyed based on the answers of persimmon growers to questionnaire. Seasonal occurrence of each developmental stage was estimated by monitoring the individuals in damaged leaves, and effect of trap site and side of sticky board were studied by yellow sticky traps at three sweet persimmon orchards in Gimhae and Jinju (orchards A and B), Gyeongnam province, Korea in 2005. P. diospyrosi gave damage to astringent persimmon as well as sweet one. The damaged area of persimmon orchard has sharply increased since 2000, reaching 446 ha nationwide; Gyeongnam province was most severely damaged, followed by Gyeongbuk and Jeonnam provinces. Most of the farmers answered that they sprayed insecticides and removed the damaged leaves to control P. diospyrosi. The overwintered adults were observed in the damaged-rolled leaves from mid May and the 1st generation adults from early-mid June. No thrips were observed in the damaged leaves after mid July. Yellow sticky trap data showed that peak adults catch of the overwintered generation was mid May, and that of the 1st generation was mid-late June in Gimhae and late June in Jinju. Sticky traps set at orchard-pine forest border caught significantly more number of the 1st generation adults than those at the orchard center, even though timing of peak catches was not different between the two sites. There was a tendency of more catches on the side of sticky trap facing pine forest than the other side facing orchard center, even though the catches on both sides showed no statistical difference.