• Korean Journal of Food Science and Technology
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• v.33 no.2
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• pp.238-244
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• 2001

The study was performed to investigate the changes of components and volatiles in citrus sudachi juice heated at 40, 50, 60, 70, 80 and $90^{\circ}C$. Total acidity, $^{\circ}Brix$, pH, organic acids, free amino acids, vitamin C, naringin, hesperidine, neohesperidin and volatiles were analyzed in fresh and heated citrus sudachi juices. The major organic acids were citric, malic and oxalic acids and their total contents were 5.27-5.48%. Citric acid content exceeded 92%, malic and oxalic acids were 3.6 and 3.2% in total orgainc acids. The organic acids decreased as heating temperature increased, but the their decreasing contents were 0.3% of total oraganic acids. Sixteen kinds of free amino acids presented in citrus sudachi juice. Major free amino acids were alanine, threonine, proline, aspargine, aspartic acid, serine, tyrosine, and trytophane and minor free amino acids were arginine, valine, glycine, lisoluecine, leucine and histidine. Free amino acids contents decreased as heating temperature increased. Vitamin C contents also decreased from 21.3 mg% to 17.3 mg% as heating temperature increased. Naringin, hesperidine and neohesperidin also slightly decreased from 304 mg% to 297.0 mg% as heating temperature increased. In the fresh and heated juices, a total of 50 volatiles were separated, of which 31 were identified. Limonene dominated in volatiles, followed by ${\gamma}-terpinene,\;{\alpha}-phellandrene$, myrcene and ${\alpha}-pinene$. ${\alpha}-Thujene$ presented in the fresh jucie but did not present in the heated juice above $50^{\circ}C$. However, ${\alpha}-Terpinolene$, terpinene-1-ol, ${\beta}-terpineol$, $cis-{\beta}-terpineol$, ${\alpha}-muurolene$, bicyclo(3.2.0)hept-6-ene, and mentha-1.4.8-triene did not presented in the fresh jucie but newly formed in the juice heated at $90^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1197-1206
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• 2014

This study compared and analyzed the physiochemical and quality characteristics of young radish kimchi made with YR-FNC or YR-GC cultivated by organic farming as well as kimchi made with young radish cultivated by chemical composting/general farming (YR-Control). YR-Control showed higher contents of water and crude protein than YR-FNC and YR-GC kimchi but lower contents of crude ash, dietary fiber, and vitamin C. YR-FNC and YR-GC kimchi also showed higher contents of P and Cu than YR-Control but lower contents of N, K, Ca, Mg, Fe, and Zn. YR-Control fermentation progressed faster than that of YR-FNC or YR-GC after 24 days, and YR-Control more rapidly reached an appropriate pH. On the other hand, YR-FNC and YR-GC kimchi fermentation progressed slow and did not reach a pH level below 5.3. For period of fermentation, YR-Control and YR-FNC kimchi showed no significant difference in reducing sugar content, whereas that of YR-GC kimchi decreased significantly after 24 days of fermentation (P<0.002). YR-FNC and YR-GC kimchi showed 1.5~3 times higher total polyphenol and flavonoid contents than YR-Control at the beginning of fermentation, whereas YR-Control and YR-FNC kimchi showed a significant increase in total polyphenol and flavonoid contents during the fermentation period. By day 7 of fermentation, YR-FNC kimchi showed higher contents of lactic acid bacteria and total microbes than YR-Control. In the sensory evaluation, YR-FNC and YR-GC kimchi showed higher preference values than YR-Control. Therefore, kimchi made from young radish cultivated by organic farming has a longer freshness period than control kimchi and is characterized by excellent sensory quality, increased physiological contents, and improved beneficial health effects.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.2
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• pp.108-117
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• 2005

Pharmaceutical byproduct sludge and cosmetic industry wastewater sludge can be used as a raw material of compost. Effects of three types of pharmaceutical byproduct sludge and one type of cosmetic industry wastewater sludge on soil properties and red pepper growth were investigated in a field based concrete pot ($2{\times}2m$). These sludges and pig manure ($5Mg\;ha^{-1}$, dry basis) were incorporated into the upper of loam soil 30 days prior to transplanting red pepper. Changes in soil properties and contents of heavy metals and toxic organic compounds in soil and plant were measured. And also plant growth measurement and bioassay of soil phytotoxicity were included. Contents of heavy metals were increased in the soils treated with the sludges. Plant growth in the sludge treatments were mostly inferior to that of NPK treatment, especially in early stage. Content of N in plant was lower in all sludge treatments at early and middle growth stages, and it was especially caused by characteristics and concentration of nitrogen and organic matter of sludges. Total yield of red pepper was highest in the NPK treatment and followed by pharmaceutical sludge 3, pig manure, pharmaceutical sludge 1, and pharmaceutical sludge 2, and the yield of cosmetic sludge treatment was considerably lower than others. HEM and PAHs contents in soil of cosmetic sludge treatment were $4.80mg\;kg^{-1}$ and $2,263.2{\mu}g\;kg^{-1}$, respectively. Root elongation of lettuce exposed to the water extract of soil treated with cosmetic sludge was about 20% of that found in the test with soil extract of non fertilization treatment. At present, raw materials of compost were authorized according to the contents of organic matter, heavy metals and product processing. Toxic organic compounds analysis and bioassay would be helpful for authorization and assessment of suitability of raw materials of compost.

• Korean Journal of Organic Agriculture
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• v.29 no.2
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• pp.223-240
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• 2021

This study was carried out to investigate the economic value of organic wheat production using gelatin·chitin microorganisms in Gwangsan-gu, Gwangju city. The soil condition of experiment field was clay loam Jisan series. The organically cultivated fields were sprayed gelatin and chitin degrading bacteria. The test was performed at conventionally cultivated field and organically cultivated field. Emergence of weed on organically cultivated field was significantly higher than conventionally cultivated field which sprayed herbicide before seeding. Weed emergence have a critical impact on grain yield. Occurrence of diseases and insect pests were higher than conventionally cultivated fields. In 2019, the amount of lodging in conventionally cultivated field were higher than conventionally cultivated field. In 2020, lodging and wet injury were occur in both field. Comparing yield element between organically and conventionally cultivated experimental area, grain yield in organically cultivated field was shown slightly higher amount than conventionally cultivated field. However in the actual yield of 2019, organically cultivated field shows 20% deceased yield because of overgrown weed. In 2020, weed emergence and yellow mosaic virus by wet injury cause 30% decease in the grain yield in organically cultivated field. Content of protein, carbohydrates, ash, water and fat in the grain were not different significance. In 2019, net incomes of conventionally cultivated wheat was 461,031 won/0.1 ha while organically cultivated wheat was 443,437 won/0.1 ha. In the rate of income, conventionally cultivated field was 83.0% as against organically cultivated field (73.3%). In 2020, net incomes of organically cultivated wheat was 437,812 won/0.1 ha while conventionally cultivated wheat was 418,281 won/0.1 ha. In the rate of income, conventionally cultivated field was 81.6% as against organically cultivated field (73.0%).

• Journal of Practical Agriculture & Fisheries Research
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• v.9 no.1
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• pp.47-58
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• 2007

New Wild Grape berry weighs approximately 3.7g, which is one fourth of the weight of the general grape wine (12.2g). The pH of New Wild Grape wine is around 3.34, which is lower by 0.3 than that (3.62) of general grape wine. It contains higher organic acids, so it has stronger sour taste. The sugar content of New Wild Grape is 17° Brix, which is higher than that (15° Brix) of general grape wine. The color of New Wild Grape is blackish, owing to the lower lightness, redness, and yellowness compared with those of general grape wine. Depending on the mixing with or without oak tree, there is little difference in the pH, organic acid, reducing sugar, and amount of alcohol after ripening for 1 year. In taste, New Wild Grape wine mixing with oak tree is evaluated better than that of the wine without oak tree. Especially, in the case of the wine mixing with oak tree's sawdust, the quality in color, taste, and smell became improved. After fermentation, the pH of New Wild Grape Wine ripened with oak tree charcoal increased from 3.82 to 3.86, as it gets more oak tree charcoal, and the organic acid decreased from 0.91㎖ to 0.86㎖. However, there is no difference in alcohol amount. Lightness in color tended to be reduced, whereas redness tended to be increased. Adding 3% of oak tree charcoal made the taste and smell improved. When fermenting New Wild Grape Wine with mixing 1% of oak tree's sawdust or 3% of oak tree charcoal, there is little difference in the pH and the organic acid, whereas there is a little difference in those of New Wild Grape Wine without addition of oak tree charcoal. As the addition of oak tree charcoal increased, the lightness and redness became higher. When fermenting New Wild Grape Wine with mixing 1% of oak tree's sawdust or 3% of oak tree charcoal in oak tree barre, the taste became improved.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.3
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• pp.103-134
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• 1977

The physiological and biochemical role of potassium for upland crops according to recent research reports and the nutritional status of potassium in Korea were reviewed. Since physical and chemical characteristics of potassium ion are different from those of sodium, potassium can not completely be replaced by sodium and replacement must be limited to minimum possible functional area. Specific roles of potassium seem to keep fine structure of biological membranes such as thylacoid membrane of chloroplast in the most efficient form and to be allosteric effector and conformation controller of various enzymes principally in carbohydrate and protein metabolism. Potassium is essential to improve the efficiency of phoro- and oxidative- phosphorylation and involve deeply in all energy required metabolisms especially synthesis of organic matter and their translocation. Potassium has many important, physiological functions such as maintenance of osmotic pressure and optimum hydration of cell colloids, consequently uptake and translocation of water resulting in higher water use efficiency and of better subcellular environment for various physiological and biochemical activities. Potassium affects uptake and translocation of mineral nutrients and quality of products. potassium itself in products may become a quality criteria due to potassium essentiality for human beings. Potassium uptake is greatly decreased by low temperature and controlled by unknown feed back mechanism of potassium in plants. Thus the luxury absorption should be reconsidered. Total potassium content of upland soil in Korea is about 3% but the exchangeable one is about 0.3 me/100g soil. All upland crops require much potassium probably due to freezing and cold weather and also due to wet damage and drought caused by uneven rainfall pattern. In barley, potassium should be high at just before freezing and just after thawing and move into grain from heading for higher yield. Use efficiency of potassium was 27% for barley and 58% in old uplands, 46% in newly opened hilly lands for soybean. Soybean plant showed potassium deficiency symptom in various fields especially in newly opened hilly lands. Potassium criteria for normal growth appear 2% $K_2O$ and 1.0 K/(Ca+Mg) (content ratio) at flower bud initiation stage for soybean. Potassium requirement in plant was high in carrot, egg plant, chinese cabbage, red pepper, raddish and tomato. Potassium content in leaves was significantly correlated with yield in chinese cabbage. Sweet potato. greatly absorbed potassium subsequently affected potassium nutrition of the following crop. In the case of potassium deficiency, root showed the greatest difference in potassium content from that of normal indicating that deficiency damages root first. Potatoes and corn showed much higher potassium content in comparison with calcium and magnesium. Forage crops from ranges showed relatively high potassium content which was significantly and positively correlated with nitrogen, phosphorus and calcium content. Percentage of orchards (apple, pear, peach, grape, and orange) insufficient in potassium ranged from 16 to 25. The leaves and soils from the good apple and pear orchards showed higher potassium content than those from the poor ones. Critical ratio of $K_2O/(CaO+MgO)$ in mulberry leaves to escape from winter death of branch tip was 0.95. In the multiple croping system, exchangeable potassium in soils after one crop was affected by the previous crops and potassium uptake seemed to be related with soil organic matter providing soil moisture and aeration. Thus, the long term and quantitative investigation of various forms of potassium including total one are needed in relation to soil, weather and croping system. Potassium uptake and efficiency may be increased by topdressing, deep placement, slow-releasing or granular fertilizer application with the consideration of rainfall pattern. In all researches for nutritional explanation including potassium of crop yield reasonable and practicable nutritional indices will most easily be obtained through multifactor analysis.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.43-50
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• 2005

We evaluated the nutritional composition of the siphon of the surf clam Tresus keenae in regard to the presence of nitrogenous [amino acids, nucleotides and their related compounds, total creatinine, betaine, trimethylamine oxide (TMAO), and trimethylamine (TMA)] and non­nitrogenous compounds (sugars and organic acids), lipid fatty-acid composition, and occurrence of minerals. The content of total free amino acids was 660.27 $\pm$ 7.94 mg/100 g, and the predominant amino acids were arginine, alanine, sarcosine, glycine, and glutamic acid. These amino acids accounted for $71\;\%$ of the total free amino acids. Among the nucleotides and their related compounds, inosine was the major component and comprised 40.38 $\pm$ 0.02 mg/100 g. Free amino acids were the largest contributor to total extracted nitrogen, comprising $49.94\%$, followed by total creatinine, betaine, nucleotides, and ammonia; the contribution of TMAO and TMA was small. For the non-nitrogenous compounds, malic acid, propionic acid, and succinic acid comprised the major portion of the ten kinds of organic acids detected, and the sugars found were glucose, maltose, and arabinose, which were estimated to be $147.0\pm7.15,\;34.45\pm1.09,\;and\;1.21\pm0.02\;mg/100\;g,$ respectively. The predominant minerals were Na and K, which comprised $11.43\pm1.06\;and\;9.46\pm1.02\;mg/100\;g,$ respectively. The major fatty acids were C22:6, C20:5, C23:0, C18:3, and C16:0 in the lipid fractions. The 23:0 level of glycolipid (GL) was the highest of any other lipid fraction. The amount of total polyunsaturated fatty acids (PUFA) in the lipid fractions was higher, ranging from $58.22\%\;in\;GL\;to\;77.1\%$ in phospholipid (PL), compared to the saturated and monounsaturated fatty acids. Of the n-3 fatty acids, C20:5 and C22:6 contributed $35.30-64.44\%$ of PUFA in the lipid fractions. The ratios of n-3 to n-6 PUFA in total lipid (TL), neutral lipid (NL), PL, and GL were 4.35, 4.26, 6.69, and 2.04, respectively.

• Korean Journal of Microbiology
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• v.21 no.2
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• pp.71-78
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• 1983

The number of aerobic free-living nitrogen fixation bacteria and factors in soil at different stands covered with Pinus rigida, Quercus acutissima and Zoysia japonica in Cheongju area were investigated from Feb. to Sept 1981. 1. The numbers of $N_2-fixation$ bacteria, according to the seasonal changes, increased gradually from winter to spring and summer. But the growth pattern revealed some differences in accordance with plant cover stands : the numbers increased abruptly in May at Pinus, May-June at Quercus and Apr. May at Zoysia stand. The pick of numbers represented in Aug. Sept, at Pinus, Jul-Aug. at Quercus and May-Jun. at Zoysia stand, respectively. 2. The interrelationship between the monthly changes of enviotnmental factors and numbers of $N_2-fixation$ bacteria at different stands, mainly depends upon the soil temperature than other soil factors (r=0.71-0.84). The numbers of $N_2-fixation$ bacteria may increase 5-7 times according to increase $10^{\circ}C$ of soil temperature, and optimal range was $20{\sim}30^{\circ}C$ for growth. Equation of the interrelation between soil temperature and numbers could be stated as follows : log y=ax+b. 3. In the case of high soil temperature, the bacterial numbers presented high level in drought periods. Therefore, the $N_2-fixation$ bacterial species in these soil seem to consist of resistant to desication. 4. The influence of soil organic matter for growth of $N_2-fixation$ bacteria indicated low conrelation. The reason may seen the content of organic matter in these soil existed abundantly above the quantities of limitation for growth. 5. In artifical gradients, the $N_2-fixation$ bacteria were predominated at $20{\sim}30^{\circ}C$ same as natural condition, pH7-8, and 20-30% of soil water contents. 6. The vertical distribution of bacteria marked decreasing trends from surface to lower layers, and the decreasing degree was shown well in Zoysia, Quercus and Pinus stand in order. But in the trees, the numbers increased at 30cm layer estimated the region of root than 20cm layer. 7. Both catalase megative and positive group of $N_2-fixation$ bacteria in soil increased according to the rise of the soil temperature. Catalase positive group was revealed as dominant group in winter, and catalase negative group revealed in summer. The change of dominant pattern was shown during Feb. to Apr.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.1
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• pp.11-17
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• 2013

Purpose: To improve glasses temple's insert processibility of CA/PEG blend, triacetin with higher specific heat values in the processing temperature range is used as second plasticizer. Methods: The total amount of plasticizer is fixed at 30 wt% by CA. To determine optimal CA/PEG/triacetin blend for glasses frame, blends with different composition ratio were examined by various analysis: thermal properties, mechanical properties, glossiness. Results: Specific heat of the CA/PEG blend increased as the content of triacetin. In CA/PEG/triacetin blends, as triacetin concentration is increased, glass transition temperature is decreased and heat conservation rate of composites is increased. Furthermore, CA/PEG/triacetin blend exhibited higher mechanical properties and similar gloss characterization with CA/PEG blend. Conclusions: It is possible to improve the processibility inserting metal support to CA temple through varying the weight ratio of PEG/triacetin. The extruded sheets of CA/PEG/triacetin blend had better glossiness and mechanical properties than those of CA/PEG blend.

• Research in Plant Disease
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• v.18 no.4
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• pp.338-348
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• 2012

Potato late blight caused by Phytophthora infestans Cooke is one of the major diseases in the cultivation of potatoes in Korea. Effect of chitosan preparations (SH-1 and SH-2) was evaluated on the inhibition of mycelial growth of P. infestans, and protective activity using detached potato leaf assay both in vivo and in the field test. SH-1 and SH-2 were showed protective activity of young plant with control values more than 95% potato late blight by inoculation with pathogens under growth chamber conditions. Mycelial growth was inhibited the radial growth over 74% at a concentration of $300{\mu}g/ml$ of both SH-1 and SH-2. Spraying with SH-1 and SH-2 on the leaves for detached leaf assay reduced disease development. The content of total polyphenol in stem was significantly increased by SH-1 and SH-2 application in the field. In field experiments, foliar application with both SH-1 and SH-2 were significantly reduced the development of late blight on potato plants. Control of late blight disease was obtained with control values of 72% and 53% by application of 1% SH-1 and SH-2, respectively, with 4 times at 7 days interval, and reduced with similar disease control values by application with 3 times at 14 days interval compared with untreated control. SH-1 and SH-2 applications increased the fresh weight of potato, and higher grade potatoes were also increased. The results showed that SH-1 and SH-2 applications can be used as eco-friendly natural fungicide for organic farming for the increase of yields and control of late blight.