• Title/Summary/Keyword: growth degree days

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Application of ATP Bioluminescence Assay for Measurement of Microbial Contamination in Fresh-cut Produce Processing Lines (신선편이 농식품 생산라인의 환경미생물 오염도 측정을 위한 ATP 검사법의 이용)

  • Choi, Ji-Weon;Lee, Hye-Eun;Kim, Chang-Kug;Kim, Won-Bae;Kim, Ji-Kang
    • Food Science and Preservation
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    • v.19 no.1
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    • pp.62-66
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    • 2012
  • With the rapid growth of fresh-cut produce market, the South Korean fresh-cut industry is facing the challenge of ensuring food safety. As the estimation of the microbial numbers in fresh-cut produce processing lines (tools, and equipment) using the conventional microbiological techniques takes days, so there is a need for faster and easier monitoring methods. This study was conducted to investigate the use of ATP bioluminescence assay to measure the degree of microbial contamination from three actual fresh-cut processing lines. The samples collected from frech-cut vegetables, and fresh-cut fruits processing plants were tested for the estimation of the bacterial number, using the ATP bioluminescence and microbiological methods. The result of former was transferred to log RLU/100 $cm^2$, and that of the latter was transferred to log CFU/100 $cm^2$. A positive linear correlation between the ATP bioluminescence assay value and aerobic-plate count was found for fresh-cut processing lines, with a correlation coefficient of 0.8772 (n=50). The results of this study indicate that ATP bioluminescence assay can be used to monitor microbial contamination in fresh-cut produce processing plants, and can help improve the hygiene therein.

Comparison of Cardinal Temperatures of Lettuce Using Bilinear, Parabolic, and Beta Distribution Functions (선형, 쌍곡선과 Beta 함수를 이용한 상추의 주요 온도 비교)

  • Cha, Mi-Kyung;Kim, Chun-Sik;Austin, Jirapa;Cho, Young-Yeol
    • Journal of Bio-Environment Control
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    • v.23 no.1
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    • pp.39-42
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    • 2014
  • The objective of this study was to estimate cardinal temperatures for germination of lettuce (Lactuca sativar L.) using bilinear, parabolic, and beta distribution functions. Seeds of lettuce were germinated in a growth chamber at 7 constant temperatures: 10, 14, 16, 20, 24, 28, and $32^{\circ}C$. Four replicates of 100 seeds were placed on two layers of filter paper in a 9 cm petri-dish. Radicle emergence of 1 mm was scored as germination. The time course of germination was modeled using a logistic function. These minimum, optimum, and maximum temperatures were estimated by regression of the inverse of time to 50% germination rate against the temperature gradient. In bilinear function, minimum, optimum, and maximum temperatures were $7.9^{\circ}C$, $23.3^{\circ}C$, and $28.0^{\circ}C$, respectively. In parabolic function, minimum, optimum, and maximum temperatures were $9.7^{\circ}C$, $19.5^{\circ}C$, and $29.4^{\circ}C$, respectively. In beta distribution function, minimum, optimum, and maximum temperatures were $3.7^{\circ}C$, $20.7^{\circ}C$ and $32.0^{\circ}C$, respectively. Minimum, optimum, and maximum ranges of temperatures were $3.7{\sim}9.7^{\circ}C$, $19.5{\sim}23.3^{\circ}C$, and $28.0{\sim}32.0^{\circ}C$, respectively.

Takju Brewing Using the Uncooked Germed Brown Rice at Second Stage Mash (2단담금에서 무증자 발아현미를 이용한 막걸리 제조)

  • 송재철;박현정
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.6
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    • pp.847-854
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    • 2003
  • In general cooked rice would be used as a major raw material for making Takju. In this case quality, taste and storage time of Takju were not fully satisfied. Fermentation conditions for Takiu mash were examined by using the germed brown rice in this study. In case of the germed brown rice on 2nd stage mash, alcohol was slowly generated in comparison with the cooked rice. Reducing sugar was slowly produced and the amount of reducing sugar was low. The sugar content was created at a uniform rate. The pH was shown to be higher in mash of the germed brown rice than that of the cooked rice. Acidity change showed a similar inclination to pH change. The degree of yeast growth on the mash of the germed brown rice was revealed to be slightly lower than that of the cooked rice. Temperature of mash was kept to be constant after 3 days from fermentation. Fusel oil produced from the mash of the germed brown rice was less gernerated in comparison with the cooked rice. Amount of amino acid in case of the germed brown rice was indicated to be higher. Takju made with the germed brown rice was shown to be 1.3 times in overall taste, 1.5 times in refreshing as compared with Takju made with the cooked rice. However there are no differences between them in flavor and color of Takju. In overall acceptance Takju made with the germed brown rice was shown to be 1.3 times as compared with Takju made with the cooked rice. In conclusion the germed brown rice was expected to be able to be better in Takju quality.

Shelf Life Extension of Steamed Bread by the Addition of Fermented Pine Needle Extract Syrup as an Ingredient (솔잎 발효액의 첨가에 의한 찐빵의 저장성 향상)

  • Choi, Dong-Man;Chung, Sun-Kyung;Lee, Dong-Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.5
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    • pp.616-621
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    • 2007
  • In order to improve the storage stability of steamed bread, fermented pine needle extract syrup potentially with several functional properties was added in manufacturing the products at levels of 8.3, 11 and 18% based on Brix degree of the dough. The manufactured bread was stored at ambient conditions and measured for quality attributes. Dough added with the fermented pine needle extract syrup maintained its pH and water activity at levels of $5.45{\sim}5.90\;and\;0.94{\sim}0.96$, which are normally suitable for yeast fermentation and for appropriate dough hardness. Addition of the extract syrup increased the bread volume by more than 20%. The bread with higher content of the pine needle extract syrup showed slower increase of bread hardness during storage, suggesting retardation of bread retrogradation. The addition of the pine needle extract syrup in bread dough also inhibited growth of the aerobic bacteria and molds on the bread surface (by $0.8{\sim}24$ in log (CFU/g) at 4 day storage). Use of higher than 11% concentration presented initially a strong fine needle flavor to the bread, which disappeared soon after 2 days. Generally addition of the pine needle extract syrup did not give negative effects on the bread quality including sensory quality. Therefore, the addition of the needle extract syrup could contribute to improving the storage stability and extending the shelf life of the bread.

Ureide Distribution in Nitrogen Fixing Soybean Plant under External Phosphorus Limitation (인산결핍 조건하에서 질소고정식물체내의 Ureide 분배)

  • Sa, Tong-Min
    • Applied Biological Chemistry
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    • v.40 no.3
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    • pp.232-237
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    • 1997
  • Soybean plants inoculated Bradrhizobium japonicum MN 110 were grown in outdoor perlite pots with nitrogen free nutrient solution containing 1.0 mM-P(control) and 0.05 mM-P(stress) and harvested at 28, 35, 42 and 49 days after transplanting (DAT) to examine the effect of phosphorus deficiency on ureide concentration of and distribution to diffrent plant organ in nitrogen fixing soybean plant during the vegetative growth. Total dry mass of control plants increased 8.9 fold and that of phosphorus deficient plant increased 2.7 fold during the experimental period. Phosphorus deficiency reduced total phosphorus and nitrogen accumulation by 80%,40% respectively, at 28 DAT and 93%, 84%, respectively, at 49 DAT. Nitrogen concentration was reduced by phosphorus deficiency in all tissues with leaf and stem tissues affected to a greater degree than nodule and root tissues at every sampling date. Phosphorus deficiency significantly reduced soluble reduced-N and ureide-N concentration in leaf and stem but did not affect those in root. The proportion of soluble reduced-N in leaf was reduced from 60% to 50% but increased from 10% to 20% in the roots. The proportion of ureide-N in leaf of control plants was higher than that in phosphorus deficient plants, whereas, roots of phosphorus deficient plants contained a higher propotion of ureide-N than those of control plants. These indicated that phosphorus deficiency not only inhibit nitrogen fixation of nodules but also restrict the translocation of fixed nitrogen out of the root system into the xylem.(Received April 4, 1997; accepted May 2, 1997)

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The Effects of Levelers on Electroplating of Thin Copper Foil for FCCL (전기도금법을 이용한 FCCL용 구리박막 제조시 레벨러의 영향 연구)

  • Kang, In-Seok;Koo, Yeon-Soo;Lee, Jae-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.2
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    • pp.67-72
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    • 2012
  • In recent days, the wire width of IC is narrowed and the degree of integration of IC is increased to obtain the higher capacity of the devices in electronic industry. And then the surface quality of FCCL(Flexible Copper Clad Laminate) became increasingly important. Surface defects on FCCL are bump, scratch, dent and so on. In particular, bumps cause low reliability of the products. Even though there are bumps on the surface, if leveling characteristic of plating solution is good, it does not develop significant bump. In this study, the leveling characteristics of additives are investigated. The objective of study is to improve the leveling characteristic and reduce the surface step through additives and plating conditions. The additives in the electrodeposition bath are critical to obtain flat surface and free of defects. In order to form flat copper surface, accelerator, suppressor and leveler are added to the stock solution. The reason for the addition of leveler is planarization surface and inhibition of the formation of micro-bump. Levelers (SO(Safranin O), MV(Methylene Violet), AB(Alcian Blue), JGB(Janus Green B), DB(Diazine Black) and PVP(Polyvinyl Pyrrolidone) are used in copper plating solution to enhance the morphology of electroplated copper. In this study, the nucleation and growth behavior of copper with variation of additives are studied. The leveling characteristics are analyzed on artificially fabricated Ni bumps.

Volume of Water Storage and Evapotranspiration by Inserted Materials at a Reservoir of Porous Grass Block (저수형 잔디블록 저수조 내 충진재료에 따른 저수량 및 초종별 증발산량)

  • Han, Seung-Ho;Choi, Joon-Soo;Yang, Geun-Mo;Yang, Byoung-E;Kang, Jin-Hyoung;Kim, Won-Tae
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.5 s.118
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    • pp.76-83
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    • 2006
  • The purpose of this study was to investigate the performance of porous grass block. For the investigation, Festuca arundinacea and Zoysia japonica 'Zenith' were planted, and the volume of evapotranspiration and remains were examined based on different materials in the water tank in the experiment of Festuca arundinacea, the volume of water storage of treatment with perlite ($10.84{\iota}/m^2$) was higher than that with drainage ($7l/m^2$). The difference between the two was $3.84/m^2$. The drainage treatment without water storage capacity showed the higher degree of dryness in turf grass. The volume of evapo-transpiration of treatment with perlite was the highest (21.57mm/week). The volume of evapotranspiration of treatment with sand was 19.57mm/week, and with treatment with drainage was 18.24mm/week. Based on the measured volume of daily evapotranspiration of $2.60{\sim}3.08mm\;d^{-1}$, it was determined that the unit with water storage capacity would store water of one to two days usage compared to unite without such storage capacity. In the experiment of Zoysia japonica 'Zenith', the volume of water storage of treatment with perlite was $10.77l/m^2$ which was similar to the former experiment. The volume of evapotranspiration of treatment with perlite and sand were 21.64mm/week and 20.64mm/week, respectively. In case of airtight water tank, the volume was measured as 22.06mm/week. Each treatment has no notable difference in the volume of evapotranspiration. In conclusion, from the investigation in this study, porous grass block with water tank was found to be effective in plant growth under low irrigation. As the ecological area ratio and vegetated porous pavement have became more emphasized, additional study of rain infiltration and reservoir effect are needed in the future.

Influence of Soil Salinity on the Growth Response and Inorganic Nutrient Content of a Millet Cultivar (토양염농도에 따른 기장의 생장반응 및 무기양분함량 변화)

  • Kim, Sun;Ryu, Jin-Hee;Kim, Young-Joo;Jeong, Jae-Hyeok;Lee, Su-Hwan;Oh, Yang-Yeol;Kim, Young-Doo;Kim, Jae-Hyen
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.61 no.2
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    • pp.113-118
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    • 2016
  • This experiment was conducted to identify the variations in inorganic nutrients and plant growth in millet (Panicum miliaceum L.) due to soil salinity. The soil series was Munpo and soil texture was silt loam. The experimental soil was amended so that the soil had salinities of $0.8dS\;m^{-1}$, $1.6dS\;m^{-1}$, $3.2dS\;m^{-1}$ and $4.8dS\;m^{-1}$. Millet was transplanted 15 days after sowing. As soil salinity increased, the degree of reduced growth was in the order of seed production > root dry matter > plant dry matter > culm length > tiller number > stem thickness > Panicle length. Seed production was decreased to 18.9% in soil salinity of $1.6dS\;m^{-1}$, 36.9% in of $3.2dS\;m^{-1}$, and 50.7% in EC of $4.8dS\;m^{-1}$. Root dry matter decreased to 35.8% in EC of $3.2dS\;m^{-1}$, and to 40.5% in EC of $4.8dS\;m^{-1}$. As soil salinity increased, Total nitrogen content increased in all aboveground parts, roots and seeds. However, There was no difference in CaO, $P_2O_5$, $K_2O$ and, MgO in soils of different salinity. On the other hand, $Na_2O$ content was higher in the order roots> shoots> seed, and in the case of roots, $Na_2O$ content increased to 1.02% in soil salinity of $4.8dS\;m^{-1}$. However, up to soil salinity of $1.6dS\;m^{-1}$, the $Na_2O$ content of the seed was similar to that in plant grown in the Control conditions($0.8dS\;m^{-1}$). In conclusion, taking into consideration economic factors, millet could be cultivated in soil with salinities of up to approximately $1.6dS\;m^{-1}$, and seed produced from reclaimedland would be suitable for human consumption.

Growth and Lodging of Paddy Rice as Affected by Paclobutrazol Application under the Different Level of Nitrogen Fertilizer (질소수준(窒素水準)이 다른 조건하(條件下)에서 Paclobutrazol 처리(處理)가 수도생장(水稻生長) 및 도복(倒伏)에 미치는 영향(影響))

  • Im, I.B.;Lee, S.Y.;Lim, M.S.
    • Korean Journal of Weed Science
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    • v.7 no.2
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    • pp.171-178
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    • 1987
  • This study was conducted to examine the possibility of complete lodging. prevention, the growth and yield of the paddy rice plant by paciobutrazol 0.6%G application at 15 days before heading under the several levels (0, 5, 10, 15, 20, 25, 30, 35, 40, 45 kg/10a) of nitrogen fertilizer in 1986. Culm length was shortened 10-15% by paclobutrazol application. The shortened rate of internode was very extreme on the 3rd and 4th internode in paclobutrazol application. Moment the height of center gravity and lodging index turned higher with increasing nitrogen fertilizer, on the other hand, those of paclobutrazol application were smaller than control. Lodging degree (0~4) was 1~3 above 25kg/10a level of nitrogen fertilizer in control, however, no more than 1 at 45kg/10a level of nitrogen fertilizer in paclobutrazol application. Ripened grain ratio and grain weight of paclobutrazol application were larger than those of control. Yield increased more 15-26% in paclobutrazol application than control. The nitrogen level of maximum yield was about 25kg/10a in control, but was 31kg/10a in paclobutrazol application.

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Studies on the Low Temperature Injury of the Rice Varieties (통일계(統一系) 수도품종(水稻品種)의 저온장해(低溫障害)에 관(關)한 연구(硏究))

  • Choi, Chang-Yoel;Kim, Moon-Kyu;Jo, Jai-Seong;Kim, Choong-Soo
    • Korean Journal of Agricultural Science
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    • v.4 no.1
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    • pp.10-20
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    • 1977
  • An expriment was conducted to determine the rate of germination under low temperature and effects of low temperature on seedling of varieties derived from the cross between Indica and Japonica type of rice. Total of 30 varieties including leading variety, Tongil, were germinated at the temperature of $10^{\circ}C$. and $15^{\circ}C$. to determine the rate of germination, and six varieties also including Tongil were planted in pot, and seedlings were exposed to the temperature of $5^{\circ}C$. and $1^{\circ}C$. for 15 days and damage of plant growth due to low temperature was observed. 1. Under the condition of $10^{\circ}C$., varieties such as Iri #323, Suwon #253, Iri #325, Milyang #22, Suwon #251, and Suwon #267 were showing over 70 percent of germination ratio, while varieties, Dodolokiwase, Milyang #23, Yusin, Iri #328, and Iri #329 were below 10 percent in germination ratio. 2. Under the condition of $15^{\circ}C$., variety Suwon #262 was shown 100 percent of germination and varieties such as Milyg an#22, Dodlokiwase, Tongil, Milyang #29, Suwon #258, Milyang #23, Milyang #24, Milyang #28 and Milyang #21 were over 90 percent in germination ratio. However, varieties such as Iri #328, Iri #329, Jinheung, and Minehikari were below 50 percent in germination rate. 3. Considering the germination rate and average days required to germination, Milyang #22 and Iri #323 were highly resistant varieties to low temperature. The rate of germination of varieties from the cross between Indica and Japonica under low temperature was not always lower than that of varieties from Japonica type of rice. 4. Most of the seedlings of varieties used were quite resistant to $1^{\circ}C$. at least for six hours. However, leaves of rice were exposed to the the temperature of $1^{\circ}C$. for 12 hours, and the withered leaves were recovered soon when put in under normal temperature. The degree of leaf withering under low temperature was lower in Milyang #15, Japonica type than in varietieties belonging to $Indica{\times}Japonica$ type of rice. 5. When the seedlings of varieties such as Josaengtongil, Tongil and Yusin were exposed to the temperature of $1^{\circ}C$. for 36 hours, 70 percent of leaves were withered and when the time of expose were doubled, the leaves were completely died. When the temperature was fluctuated, over 75 percent of leaves were died, while 65 percent of leaves of Milyang #15 were died when exposed to $1^{\circ}C$, for 72 hours. 6. Significant growth retardation was observed for all entries when exposed to $1^{\circ}C$. for 24 to 36 hours. The growth retardation was apparently increased as the time of expose was extended.

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