• Membrane and Water Treatment
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• v.7 no.1
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• pp.11-22
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• 2016

The characterization of treatment performance with respect to mixed liquor suspended solids (MLSS) concentration enables greater control over system performance and contaminant removal efficiency. Hybrid membrane bioreactors (HMBRs) have yet to be well characterized in this regard, particularly in the context of greywater treatment. The aim of this study, therefore, was to determine the optimal MLSS concentration for a decentralized HMBR greywater reclamation system under typical loading conditions. Treatment performance was measured at MLSS concentrations ranging from 1000 to 4000 mg/L. The treated effluent was characterized in terms of biochemical oxygen demand ($BOD_5$), chemical oxygen demand (COD), turbidity, ammonia ($NH_3$), total phosphorus (TP), total kjeldahl nitrogen (TKN), and total nitrogen (TN). An MLSS concentration ranging from 3000 to 4000 mg/L yielded optimal results, with $BOD_5$, COD, turbidity, $NH_3$, TP, TKN, and TN removals reaching 99.2%, 97.8%, 99.8%, 99.9%, 97.9%, 95.1%, and 44.8%, respectively. The corresponding food-to-microorganism ratio during these trials was approximately 0.23 to 0.28. Operation at an MLSS concentration of 1000 mg/L resulted in an irrecoverable loss of floc, and contaminant residuals exceeded typical guideline values for reuse in non-potable water applications. Therefore, it is suggested that operation at or below this threshold be avoided.

• Journal of Life Science
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• v.9 no.2
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• pp.19-23
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• 1999

Bisphenol-A and related conpounds recently have been reported to be estrogenic since it has been demonstrared in laboratory stuides that they mimic the effects of estrogen. Bisphenol-A refered to as "environmental estrogen" are suspected of causing health effect in living body through disruption of endocdrine system. In this review, the occurrence, environmental fate, and biological effects of bisphenol-A are presented. To provide understanding to the potential for endocrine disruption due to environmental estrogen, the physiology of bisphenol-A mammalian and fish is also reviewed. For empty can, the migrationof bisphenol-A form food conducted epoxy coating was effected by the test conditions and it increased in order to water and 4% acetic acid. Extracts from foods packed in lacquer coated can also showed estrogenic activity. Bisphenol-A was found as a contaminant not only in the liquid food cans, but also in water autoclave in can. The used of coating certain food-packaging material may require closer scrutiny to determine when bisphenol-A contribute to advert exposure of consumers to estrogenic xenobiotics. Human breast cancer MCF cell added bisphenol-A cultivated to study the ability of bisphenol-A to elicit of bisphenol-A estrogenic bioresponse in this system. Bisphenol-A, similar to estradiol, induced PR activation in transiently transfected anterior and posterior pituitary cells.

• Journal of Environmental Health Sciences
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• v.43 no.4
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• pp.307-313
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• 2017

Objectives: Chemicals derived from various environment media contaminates food across the food supply chain. In Korea, levels of contaminants in food have been sporadically measured by monitoring programs of different government agencies. There is difficulty with data compilation and integrated analysis across media. Therefore, the aim of this study was to propose an overall integrated database and analytical platform design for the 'ECO-FOOD NET (Environmental COntaminant reduction platform for FOOD through an interagency collaboration NETwork)', a tool to support the reduction of environmental contaminants in food. Methods: We developed a new data structure and standardized protocols for the compilation of integrated data. In addition, we conducted subject-oriented logical and physical relational database modeling and created the architecture design of the platform. Results: We established a standardized code system related to exposure media and route, analysis method and food matrix. In addition, we designed the seven software modules of 'About the System', 'Introduction to Interagency Work', 'Media-Chemicals Profiles', 'Method Bank', 'Monitoring Data Base', 'Integrated Media Analysis', and 'Risk-Benefit Analysis'. Conclusions: This study will contribute to decision-making as a tool for executing risk management, such as sustainable reduction policies of contaminants in food.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1234-1243
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• 2000

A method for quantitative determination of styrene dimer and trimer, which are suspected as endocrine disruptors, in foods and containers was studied. For residual contents of styrene dimer and trimer in two-kinds of containers, which contained instant noodle and yogurt, sample pieces were completely dissolved in tetrahydrofuran. The polymer was precipitated with n-hexane, a portion of supernatant was concentrated for analysis. A sensitive method was also optimized for the quantification of styrene dimer and trimer in foods such as instant cup noodle and yogurt by using GC/MS. Limits of Detection were about 3.2-87.0 ppb for styrene dimers and trimers. The highest recovery was obtained by extraction with acetone/hexane(1:1), followed by florisil clean-up. The levels of styrene dimer and trimer migrated by food simulants were much higher in heptane.

• Food Science of Animal Resources
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• v.36 no.1
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• pp.100-108
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• 2016

Microbiological contamination of eggs should be prevented in the poultry industry, as poultry is one of the major reservoirs of human Salmonella. ClO₂ gas has been reported to be an effective disinfectant in various industry fields, particularly the food industry. The aims of this study were to evaluate the antimicrobial effect of chlorine dioxide gas on two strains of Salmonella inoculated onto eggshells under various experimental conditions including concentrations, contact time, humidity, and percentage organic matter. As a result, it was shown that chlorine dioxide gas under wet conditions was more effective in inactivating Salmonella Enteritidis and Salmonella Gallinarum compared to that under dry conditions independently of the presence of organic matter (yeast extract). Under wet conditions, a greater than 4 log reduction in bacterial populations was achieved after 30 min of exposure to ClO₂ each at 20 ppm, 40 ppm, and 80 ppm against S. Enteritidis; 40 ppm and 80 ppm against S. Gallinarum. These results suggest that chlorine dioxide gas is an effective agent for controlling Salmonella, the most prevalent contaminant in the egg industry.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.640-653
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• 2022

Deoxynivalenol (DON) is the most common mycotoxin contaminant of cereal-based food and animal feed. The toxicity of DON is very low compared to that of other toxins; however, the most prominent signs of DON exposure include inappetence and body weight loss, which causes considerable economic losses in the livestock industry. This review summarizes critical studies on biological DON mycotoxin mitigation strategies and the respective in vitro and in vivo intestinal effects. Focus areas include growth performance, gut health in terms of intestinal histomorphology, epithelial barrier functions, the intestinal immune system and microflora, and short-chain fatty acid production in the intestines. In addition, DON detoxification and modulation of these parameters, through biological supplements, are discussed. Biological detoxification of DON using microorganisms can attenuate DON toxicity by modulating gut microbiota and improving gut health with or without influencing the growth performance of pigs. However, the use of microorganisms as feed additives to livestock for mycotoxins detoxification needs more research before commercial use.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.4
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• pp.502-511
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• 1997

This study was to Investigate the consumer's understanding and purchasing foods, which were produced by organic agricultured method. The results of this study were as follows: 1. When shopping foods, the items which were deeply considered were taste of family and food safety. 2 Contaminants which were considered to be dangerous were, in decreasing order, agricultural chemical residue, food additives, environmental contaminant, and microbial hazard. Consumer's perception to agricultural chemical residue In foods was 'be much serious' and over 4.0 by Likert 5 scale. 3. Among of characteristics which was associated with organic farmming foods, taste and nutrition were considered the least important characteristic, whereas safety and good health were considered the most important characteristic. 4. The foods which were thought to be polluted by agricultural chemical residue were, in decreasing order fruit, vegetable, cereal, egg, meat, milk, and fish & shellfish. 5. The respondants' purchasing degree for organic farmming foods was 'often purchase' and 3.44 by Likert 5 scale. These result showed significant difference for age(p＜0.05), for education level (p＜0.05), for income(p＜0.05) and for food expenditure(p＜0.05), respectively 6. The type of organic farmming food which frequently purchased were, in decreasing order, vegetable. fruit, egg, cereal, milk, and meat. The reasons why consumer purchased organic farmming food were, in decreasing order, no pesticide/therbicides, no artifical fertilizer, no growth regulators, residue free, and good quality. 7. 78% of respondants Indicated that they bought organic farmming food in this year increasely or same as last year and 91.9% of respondants Indicated that they plan to buy organic farmming foods in next year.

• Environmental Mutagens and Carcinogens
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• v.26 no.3
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• pp.69-76
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• 2006

2,3,7,8-Tetrachlorodibenzo-$\rho$-dioxin(TCDD) is a ubiquitous, persistent environmental contaminant and the most powerful carcinogen categorized by IARC. Although the mechanism of carcinogenesis by TCDD is poorly understood, several studies have shown that the skin is one of target organs far TCDD. In this study, we investigated the neoplastic transformation of human keratinocyte-derived cell line, HaCaT, by chemical transformation method using N-methyl-N'-nitro-N-nitrorsoguanidine(MNNG) and TCDD. We found that subsequent exposure to TCDD for 3 weeks after initial exposure to MNNG markedly induced transformed cells. It was suggested that TCDD can act as a potent promoter in HaCaT cells. Furthermore, these transformed cells showed morphological alternations in soft agar and increased telomerase activity. Therefore, the TCDD treatment of HaCaT cells by initiated with MNNG could promote neoplastic transformation without stimulation by exogenous growth factors. As a result, TCDD had a strong potency as a promoter in nontumorigenic immortalized human epidermal keratinocytes.

• Journal of Microbiology and Biotechnology
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• v.23 no.5
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• pp.674-680
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• 2013

Yeast Dekkera/Brettanomyces bruxellensis is probably the most common contaminant in wineries and ethanol production processes. The considerable economic losses caused by this yeast, but also its ability to produce and tolerate high ethanol concentrations, make it an attractive subject for research with potential for industrial applications. Unfortunately, efforts to understand the biology of D. bruxellensis and facilitate its broader use in industry are hampered by the lack of adequate procedures for delivery of exogenous DNA into this organism. Here we describe the development of transformation protocols (spheroplast transformation, LiAc/PEG method, and electroporation) and report the first genetic transformation of yeast D. bruxellensis. A linear heterologous DNA fragment carrying the kanMX4 sequence was used for transformation, which allowed transformants to be selected on plates containing geneticin. We found the spheroplast transformation method using 1M sorbitol as osmotic stabilizer to be inappropriate because sorbitol strikingly decreases the plating efficiency of both D. bruxellensis spheroplast and intact cells. However, we managed to modify the LiAc/PEG transformation method and electroporation to accommodate D. bruxellensis transformation, achieving efficiencies of 0.6-16 and 10-20 transformants/${\mu}g$ DNA, respectively. The stability of the transformants ranged from 93.6% to 100%. All putative transformants were analyzed by Southern blot using the kanMX4 sequence as a hybridization probe, which confirmed that the transforming DNA fragment had integrated into the genome. The results of the molecular analysis were consistent with the expected illegitimate integration of a heterologous transforming fragment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.917-920
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• 2004

The migration potential of volatile organic solvents widely employed in the printing process of food packaging was investigated by using a closed experimental system, which contained a food sample and a paper sheet spiked with the contaminant solvents. The studied organic compounds included toluene and p,m,o-xylene which are relatively highly volatile. Typical food samples of caramel, beef jerky and butter were selected based on their chemical composition and were assigned to the migration system at 10, 25 and 4$0^{\circ}C$. The equilibrated migration level was very high with almost complete transfer in the butter with high fat, while caramel of high carbohydrate content and beef jerky of high protein showed migration degree of 37∼56% and 37∼77%, respectively. Temperature did significantly influence the migration on beef jerky with higher level at higher temperature. There was no difference in the migration level among the solvents.