• Title/Summary/Keyword: Organic system

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Synthesis of an Aspartame Precursor Using Thermolysin in Organic Two-Phase System (유기용매 이상계에서 Thermolysin에 의한 아스파탐 전구체 생산)

  • 이인영;안경섭;이선복
    • Microbiology and Biotechnology Letters
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    • v.20 no.1
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    • pp.61-67
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    • 1992

  • The synthesis of N-benzyloxycarbonyl-L-aspartyl-L-phenylalanine methyl ester(ZAPM), a precursor of aspartame, from N-benzyloxycarbonyl-L-aspartic acid(Z-Asp) and L-phenylalanine methyl ester hydrochloride(L-PM-HCl) was investigated in ethylacetate-MES buffer two-phase system using thermolysin. In organic two-phase system, the degree of spontaneous hydrolysis of L-PM. HCl was significantly reduced with increasing the volume ratio of organic to aqueous phase. Stability of thermolysin in organic two-phase system was found to be higher than that in MES buffer solution. More than 90% of initial enzyme activity was maintained after 10 days of incubation in case that the volume of organic phase was equal to that of buffer phase, while the half life of thermolysin was about 2 days in aqueous buffer solution. The results of partitioning of substrates and product in organic two-phase system showed that the difference in partition coefficients between substrates and product was maximum at pH 5.5. The optimal pH for 2-APM synthesis in organic two-phase system was found to be 5.5-5.8, which is consistent with the value expected from the partition experiments. As the concentration of substrates was increased the conversion yield of Z-APM was increased with concomitant reduction of L-PMqHC1 hydrolysis. In case that the concentration of L-PM-HCl and Z-Asp were 160 mM and 80 mM respectively, the conversion yield of Z-APM reached 90% after 28 hrs of reaction. The yield obtained at different volume ratio of organic phase compares well with the predicted equilibrium constant in biphasic system.

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A Study on the Marketing Strategy of Environment-friendly Agricultural Products (친환경.유기농산물 생산.유통.소비시장 현황 분석 -가격경쟁력 제고 방안을 중심으로-)

  • Hwang, Jae-Hyun
    • Korean Journal of Organic Agriculture
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    • v.17 no.3
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    • pp.327-345
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    • 2009

  • Environment-friendly agricultural products market has been experiencing various change through the quantitative growth in Korea. The food safety is considered seriously and the interest of the consumer is increasing about environment-friendly agricultural products and organic agricultural products. Environment-friendly agricultural products is encouraged in the link of the counter-measure which follows in the market opening. This research aims at making shorter the distance between the productive person and the consumer and to improve the income for organic farm and the price competitiveness for Environment-friendly agricultural products through the present condition analysis for organic produce's production, distribution and consumption market. To solve the problems above, the development of strategies for the establishment of distribution system for the organic produce's stable supply and the improvement of price competitiveness, the establishment of the cooperating system on the produce's demand and supply, the improvement of consumer's reliability by reinforcement with connectivity and transparency of the process, and the vitalization of regional economy and the exchange of rural and city area are needed.

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Nitrogen Fixation of legumes and Cropping System for Organic Forage Production (두과 작물의 질소고정과 유기조사료생산을 위한 작부체계)

  • 이효원;박형수
    • Korean Journal of Organic Agriculture
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    • v.10 no.1
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    • pp.49-63
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    • 2002

  • In order to supply 85% of total organic feed in ruminants and 80% in non-ruminants for organic animal production, nitrogen fixation ability of legume should be used in domestic roughages production. 50% of Europe organic farmer use intercropping legume in as green manure. This article is dealing with amount of biologically fixed nitrogen used by legumes and methods for estimating the transfer of biologically fixed N in rotation and separating the N benefit into fixed N and non-fixed N components are reviewed. Available data indicate that transfer amount of N to non legumes was from 50∼9.6(kg/ha) in legume-cereal rotations and proportion of legume N varied with seasons, 90% in summer, 50% in autumn. The important point in cropping system for legumes have to be included for organic forage production 6 year rotation is based on pasture system of 3 year pasture + 2 year annual(com, sudangrass), again pasture. Rye, barly and Italian ryegrass+legumes(vetch, crimson and pea) can be one of option in spring, com, soybean, sudangrass and Japanese bamyard millet would be seeded after spring harvest in the field. Farmer can make good use of rice paddy field as forge production potential area after harvesting rice. Italian, burly and rye+vetch and crimsonclover may be grown in autumn or spring time at the rice field.

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Environmental Friendly Function and Safe Food Production by Organic Agriculture in Europe (선진 유럽유기농업의 환경보전 기능과 안전농산물 생산-한국유기농업의 발전을 위한 농업정책적 제안-)

  • 정길생;손상목;이윤건
    • Korean Journal of Organic Agriculture
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    • v.5 no.1
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    • pp.45-66
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    • 1996

  • In Korea there is still no basic standard for organic agriculture and organic farmers in Korea do not follow the minimum requirements of IFOAM basic standard Most of them just practice the organic agriculture applying organic fertilizer, commercial seed without legume, rotation and green manure. But they believe this system is a absolutely environmental friendly agricultural system and it produce a safe agricultural product since they are not aware of the basic standard of organic agriculture at all. The overuse of organic fertilizer by some organic farmer have caused some severe problems risk for nitrate and phosphate leaching. In soil profile showed the potential risk for nitrate and phosphate leaching. In the paper, it is discussed on the environmental friendly function and the safe vegetable production by european organic agriculture which keeps the internationally recognized basic standards of organic agriculture. Therefore it is strongly recommended that korean organic farmer have to follow the IFOAM it is strongly in order to practice the environmental agriculture and produce the safe food. And it is also necessary to introduce to Korea the basic standard of organic agriculture which coincides with IFOAM's and Codex of FAO/WHO immediately if they really want to practice an organic agriculture in the country.

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