• 한국물환경학회지
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• 제40권1호
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• pp.11-18
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• 2024

Recently, enhanced in situ bioremediation using slow substrate release techniques has been actively researched for managing TCE-contaminated groundwater. This study conducted a lab-scale batch reactor experiment to evaluate the feasibility of natural attenuation for TCE dechlorination using microsized corn-oil droplet (MOD) as an activator considering the following three factors: 1) TCE dechlorination in the presence or absence of MOD; 2) TCE dechlorination in the presence or absence of inactivator of native microbial activity; and 3) MOD concentration effects on TCE dechlorination. Batch reactors were constructed using site groundwater and soil in which Dehalococcoides bacteria were present. Without MOD, TCE was decomposed into dichloroethylene (DCE). However, other by-products of TCE dechlorination were not detected. With MOD, DCE, vinyl chloride (VC), and ethylene (ETH) were sequentially observed. This result confirmed that MOD effectively supplied electrons to complete dechlorination of TCE to ETH. However, when an excess of MOD was provided, it formed unfavorable conditions for anaerobic digestion because dechlorination reaction did not proceed while propionic acid was accumulated after DCE was generated. Therefore, if an appropriate amount of MOD is supplied, MOD can be effectively used as a natural reduction activator to promote biodegradation in an aquifer contaminated by TCE.

• 한국식품위생안전성학회지
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• 제18권2호
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• pp.87-93
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• 2003

본 연구는 aflatoxin이 오염된 옥수수에서 각 전처치 방법과 조리 및 가공 방법에 따라 aflatoxin이 감소되는 정도를 관찰하고자 수행되었다. Aspergillus parasiticus ATCC 15517을 접종하여 aflatoxin을 생성시킨 옥수수(GCB70, 미국산)에 태양 광선 조사, UV 조사 및 물 세척 등의 전처치를 실시하였으며, 각 전처치 후의 시료를 옥수수의 일반적인 조리 및 가공 방법(끓이기, 찌기, 굽기 및 튀기기)에 따라 죽, 떡, 빵 및 팝콘을 만들었다. Aflatoxin이 생성된 옥수수 시료(AC)와 전처치에 따른 부과물로서 AC에 태양 광선을 7일 조사시킨 시료(SC), UV를 56시간(7일간) 조사시킨 시료(UC)및 물 세척을 3회 수행한 시료(WC), 그리고 이들의 조리 및 가공 완성품에 대한 aflatoxin 함량을 HPLC로 정량하였다. AC의 total aflatoxin함량은 전처치 시료에서는 태양 광선 조사시와 UV조사시(UC)에 유의하게 감소하였으며(p<0.05), 물 세척시에는 감소하였으나 유의한 감소는 아니었다. AC, SC, UC 및 WC를 조리 및 가공하였을 때 평균적으로 죽＞팝콘>떡＞빵의 순으로 aflatoxin이 감소되었다. 이로부터 aflatoxin에 오염된 옥수수의 조리 및 가공전 태양 광선 조사와 UV조사는 aflatoxin분해에 효과적인 것으로 나타났다. 또한 끓이기, 찌기, 굽기 및 튀기기 등의 조리 및 가공 방법은 aflatoxin의 감소에 도움이 되며, 특히 열에 지속적으로 노출되는 것이 가장 효과적인 것으로 나타났다. Aflatoxin이 오염된 옥수수에서 aflatoxin을 식품 중 기준치 이하로 감소시키기 위하여 더 많은 연구가 필요하다.

• Journal of Forest and Environmental Science
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• 제27권3호
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• pp.183-194
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• 2011

This study reviewed on the research trend of sources and utilization of the byproducts(Lignin) from bioethanol production process with lignocellulosic biomass such as wood, agri-processing by-products(corn fiber, sugarcane bagasse etc.) and energy crops(switch grass, poplar, Miscanthus etc.). During biochemical conversion process, only Cellulose and hemicellulosic fractions are converted into fermentable sugar, but lignin which represents the third largest fraction of lignocellulosic biomass is not convertible into fermentable sugars. It is therefore extremely important to recover and convert biomass-derived Lignin into high-value products to maintain economic competitiveness of cellulosic ethanol processes. It was introduced that lignin types and characteristics were different from various isolation methods and biomass sources. Also utilization and potentiality for market of those were discussed.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.25-30
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• 2019

본 연구에서는 상온 저장이 가능하며 별도의 처리 없이 바로 섭취할 수 있는 통초당옥수수를 위한 최적 살균법을 도출하고 저장기간동안 최적 살균된 초당옥수수의 품질인자를 분석하였다. 살균 시 유통기한 확보 및 초당옥수수의 고유한 특징인 아삭한 식감이 가열처리에 의하여 감소되는 것을 최소화 하기 위해 비가열 전처리 공정으로서 알코올 세척을 도입하였으며, 냉점은 초당옥수수의 속대와 중심 사이로 하였다. 초당옥수수의 표면은 알코올 세척을 통하여 1 log CFU/g 이상을 감소시킨 후 $F_{121.1}=4$분을를 만족하도록 가열하여 $25^{\circ}C$ 인큐베이터에서 9개월간 저장하면서 대조군으로서 일반적인 증숙의 방법으로 가열한 초당옥수수의 품질과 비교하였다. 알코올 처리 및 가열 살균한 초당 옥수수의 조직감은 대조군의 조직감 대비 30%이내를 유지하여 최소 $464.50{\pm}103.35g$에서 최대 $514.50{\pm}81.83g$값을 나타내었으며, 당도는 샘플 간의 차이가 다소 있었으나 최소 $28.83{\pm}1.05%$에서 최대 $34.36{\pm}0.42%$값으로 대조군에 대비하여 30% 이내 당도를 유지하였다. 초당 옥수수 겉표면 황색도는 대조군 대비 5% 이상 향상되어 최대 $34.36{\pm}0.42$값을 나타내었으며, 미생물 검사에서는 일반세균과 진균류가 저장 9개월 동안 검출되지 않았다. 이러한 연구결과는 가열살균한 초당옥수수의 품질변화가 최소화되면서 6개월 이상의 상온유통이 가능한 최적 살균 방법을 도출하였으며, 이에 따라 가열에 의하여 식품 본연의 조직감 감소를 최소화하면서 상온유통이 가능한 살균제품에 이용될 수 있다.

• 한국식품위생안전성학회지
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• 제28권2호
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• pp.158-167
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• 2013

This study was carried out to assess the safety of cereals and their products (20 species, 205 samples) distributed in Gyeonggi province by analyzing contamination levels such as exposure frequency of Aflatoxins and Deoxynivalenol (DON). Aflatoxins were detected in 16 (8%) samples in total with a range of 0.01~27.88 ${\mu}g/kg$, including 3 of 9 bake flour (33%), 2 of 6 dried corn (33%), 3 of 12 frying flour (25%) and 2 of 11 sorghum (18%). DON was found in 56 (27%) samples including 11 of 13 adlay (85%), 6 of 8 wheat (75%), 6 of 10 processed corn for popcorn (60%), 6 of 11 sorghum (55%) and 7 of 16 barley (44%) with a range of 2.2~754.4 ${\mu}g/kg$. In particular, both Aflatoxins and DON were detected in 8 samples (2 millet, 2 wheat, 1 sorghum, 1 adlay, 1 dried corn, 1 bake flour) simultaneously. As a result of this study, we found that an adult is exposed to Aflatoxins of $0.80({\times})10^{-3}{\mu}g/kg$ b.w./day and DON of 0.18 ${\mu}g/kg$ b.w./day. The quantity of exposure to DON amounted to 18.5 percentage level compared with PMTDI 1 ${\mu}g/kg$ b.w./day suggested on JECFA, therefore we can assess that the possibility of health risks by intake cereals distributed in Gyeonggi province is low. However the concentration of Aflatoxins in one dried corn was 27.88 ${\mu}g/kg$ which was over the maximum residue limits (MRL) suggested on internal and external level, the monitoring about mycotoxin should be conducted on continuously.

• 한국미생물·생명공학회지
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• 제9권4호
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• pp.253-261
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• 1981

Fermented foods available in Korea may be classified into four groups, namely, fermented soybean products, fermented cereal products, fermented vegetable products, and fermented fishery products based on raw materials used. The representative fermented foods based on soybean are Kanjang(soysauce), Doenjang(fermented soybean pastes), and Kochujang(red pepper added-fermented soybean paste). Such fermented products are made using Meju(functioning as a starter and prepared by fermentation of steamed soybean mash) as an essential ingredient, and used widely as a soup base and/or in seasoning side-dishes for everyday meals year around. Excepting Sikhae, all fermented products based on rice and other cereal grains are of alcoholic nature. Takju (Makgeolli) used to be made using rice as the major raw material, however, mainly due to the shortage of rice in recent years, other cereals, such as, barely, corn, and wheat flours are also used to replace rice today. Owing to such changes in the raw materials. the popularity of Takju has been somewhat reduced, yet it is still widely consumed in rural areas. Although Chungju is a popular rice wine with superior qualify over Takju, the amount consumed is considerably limited. The highest qualify rice wine, Bupju, in particular, is made by a low temperature fermentation using glutinous rice. Kimchi is an unique fermented vegetable product of long tradition in Korea. Although it was for consumption mainly in winter season serving as a source of vitamins, today it is widely used throughout the year. Except Kkakdugi and Dongchimi, all of the fermented vegetable products contain salted Korean cabbage as an essential item, while they abound in varieties depending on material composition and methods of processing, and also on seasons and localities Next to Kimchi in this category is Kkakdugi made of raddish in popularity and quantity consumed. The four groups of fermented food products described above are reviewed in some detail and evaluated in terms of their nutritional significances, processes and microorganisms involved. and their commercial potentials. Jeotkal (or Jeot) is a name given to all fermented products of fishery origin. A number of Jeot can be prepared by adding salt and allowing fermentation to the raw materials such as shrimp, anchovy octopus, clam, oyster, etc.

• 식물병연구
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• 제28권4호
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• pp.179-194
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• 2022

이 논문에서는 2000년 이후 우리나라의 곡류와 곡류 가공품의 곰팡이독소 오염실태를 보고한 논문들을 작물별로 분석하였다. 보리, 쌀, 옥수수는 다른 곡류보다 많이 조사되었다. 모든 곡류와 곡류의 가공품에 공통으로 발생한 독소는 데옥시니발레놀과 제랄레논이었다. 니발레놀은 분석한 모든 시료에서 검출되었지만 보리, 쌀, 귀리에서 더욱 빈번하거나 주로 검출되었다. 푸모니신은 옥수수와 수수 외에 율무, 기장, 쌀에서도 검출되었다. 율무와 기장은 푸모니신과 제랄레논이 가장 빈번하게 검출되는 오염양상이 유사하였다. 가장 빈번하게 검출수준이 국내기준(최대기준)을 초과한 곰팡이독소는 제랄레논이었고 다음은 데옥시니발레놀과 아플라톡신 순이었다. 그러나 대부분의 오염수준은 각 곰팡이독소의 최대기준 미만이었다. 이 결과는 보리, 쌀, 옥수수, 수수, 기장, 율무 등이 다른 곡류에 비해 곰팡이독소 오염에 취약하며 따라서 이들 농산물의 지속적인 모니터링과 안전관리가 필요함을 보여준다.

• 한국미생물·생명공학회지
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• 제17권2호
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• pp.136-141
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• 1989

Streptomyces sp. 4M-2의 생전분 분해효소를 황산 암모니움 염석과 이온교환 크로마토그라피 및 Gel 여과 등으로 비활성이 51.22 RSU/mg, 수율 4.5%로 정제할 수 있었다. 정제효소의 분자량은 102,000이었으며 생옥수수 전분에 대한 Km값은 44.44mg/m1 이었다 정제효소의 작용 최적온도는42$^{\circ}C$, pH는 5.5였고 $Ca^{2+}$와 $Ba^{2+}$의 첨가에 의해 효소활성이 증가되었다. 정제효소는 옥수수 amylose를 가장 잘 분해하고 감자전분도 비교적 잘 분해하였다. 이 효소에 의한 옥수수 생전분의 분해산물은 주로 maltose와 maltotriose였고 소량의 glucose와 oligosaccharide도 검출되었으므로 $\alpha$-amylase 계통의 효소로 추정된다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• 한국환경보건학회지
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• 제20권3호
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• pp.49-53
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• 1994

To isolate the ochratoxin A producing strains from agricultural products and soil in Youngnam districts, rice (37), unhulled rice (10), barley (20), unhulled barley (3), corn (21), soil (26), meju (25), malt (8), soybean (26) and peanut (15) were collected from homes and markets of Youngnam districts through September 1992 to November 1992. 187 strains of Aspergillus spp. and Penicillium spp. were isolated from 191 samples. As a result of screening by TLC, 36 strains expressed fluorescent spot and a same Rf value of standard ochratoxin A, and 9 strains of them were identified as ochratoxin A producing strains by HPLC.