• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.36-40
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• 2015

This study examined the disinfection in combined sewer overflows (CSOs) by pulsed ultraviolet (PUV). The reflectors (stainless steel. mirror, aluminium foil, aluminium (1050), aluminium (6061), aluminium (5052), and aluminium mirror) of PUV irradiation was performed in a 90 L stainless reactor at a constant temperature of $20^{\circ}C$ and an applied power of 4000 W. The reflection efficiency of reflectors were showed 1.00 (aluminium mirror) ~ 1.48 (aluminium foil) does. The case of a rough surface analysis using SEM showed high reflectance, was the case of a smooth surface and a low reflectivity. Pseudo first-order rate constant calculated results, has a higher reflectivity values were more than twice as high compared to the low reflectivity. Affected Total coliforms disinfection time, depending on the type of reflector is considered.

• Food Science and Biotechnology
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• 제16권6호
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• pp.948-953
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• 2007

The powdered cereal sunsik is a partially thermal-processed product that required safety evaluations for food-borne pathogens. Thirty-six sunsik products from Korean markets were collected and analyzed for contamination by total viable cell counts, coliforms, Escherichia coli, and the spore-forming Clostridium perfringens and Bacillus cereus. Enterobacter sakazakii, as a newly emerging pathogen, was also analyzed. Approximately 28% of sunsik were contaminated at 5 log CFU/g for total viable counts. Coliforms and E. coli were detected in 33 and 4% of the samples, respectively. The spore-forming B. cereus was found in 42% of the samples at a maximal level of 3 log CFU/g on average. About 6% the samples were contaminated with Cl. perfringens at an average level of 15 CFU/g. Forty-five % of sunsik contained E. sakazakii, at levels from 0.007 to over 1.1 cell/g by MPN method. In addition, one sunsik product for infants and children showed over 3 log CFU/g for both B. cereus and E. sakazaki. Therefore, concern should be placed on controlling for microbial hazards such as B. cereus and E. sakazakii in sunsik, particularly for the products fed to infants under 6 months of age.

• 한국환경보건학회지
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• 제6권1호
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• pp.57-63
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• 1979

A study on consecutive changes of milk was carried out to determine the changes of milk components and microorganisms by different containers. The containers included in this study were glass bottles, polyethylene packs, polystyrene bottles and aluminum foils. The number of total microorganisms and coliforms, contents of milk fat and vitamin A were tested. The results obtained were as follows: 1) The number of total microorganisms exceeded the legal criteria within 2-3 days at 4$\circ$C, 24 hours at room temperature (20-23$\circ$C) and 3 hours at 35$\circ$C. 2) The number of coliforms in milk contained in glass bottles exceeded the legal criteria within 3 days at 4$\circ$C, that of glass bottles and polyethylene packs within 12 hours at room temperature (20-23$\circ$C), that of polyethylene packs and polystyrene bottles within 6 hours at 35$\circ$C, and that of glass bottles within 9 hours at 35$\circ$C respectively. 3) The milk fat contents by di'fferent containers were not changed at all. 4) Vitamin A contents were reduced by a slight exposure to sunlight. The destruction rates of all containers were the highest in an hour after exposure to sunlight. The rates by different containers were 50.1% in glass bottles, 47.6% in polyethylene packs, 30.4% in polystyrene bottles in an hour after exposure respectively. After an hour exposure, the destruction rates gradually decreased. The vitamin A destruction rate of glass bottles were the highest, and that of polyethylene packs were next, and that of polystyrene bottles were the lowest 5) The changes of pH of milk were high in the following order: the milk in glass bottles, polyethylene packs, and polystyrene bottles. pH of milk in aluminum foils were not changed.

• Asian-Australasian Journal of Animal Sciences
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• 제30권9호
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• pp.1285-1291
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• 2017

Objective: A trial was conducted from 11 to 42 d post-hatch to investigate the effectiveness of the supplementation of a multiple-enzyme preparation (Natuzyme Plus) in a wheat-based diet on digesta viscosity, pH and microbial population, villus morphology, feed passage time, nutrient retention, carcass characteristics, blood lipid parameters and growth performance of broiler chickens. Methods: Three hundreds 10-d-old male Ross 308 chicks were allocated to three diets with five replicates of 20 birds per replicate. Dietary treatments were i) a wheat-based diet (W), ii) W+Natuzyme Plus (WN; 500 mg/kg of the diet), and iii) a corn-based diet (C). Results: Birds fed on the C diet had higher average daily gain (ADG, p<0.01), villus height (VH, p<0.01), total tract apparent retention (TTAR) of nitrogen (NT, p<0.01) and ether extract (EE, p<0.01), nitrogen-corrected apparent metabolizable energy ($AME_n$, p<0.05), relative weight (RW, % of body weight) of carcass (p<0.05), blood concentration of triglyceride (TG, on d 40 [p<0.01]), total cholesterol (TC, on d 22 [p<0.05]) and low density lipoprotein (LDL, on d 22 [p<0.01] and 40 [p<0.05]), and also lower feed conversion ratio (FCR, p<0.01), digesta viscosity (p<0.01), count of coliforms (p<0.01) and Escherichia coli (p<0.01) and epithelium thickness (ET, p<0.05) than those fed on the W diet. ADG, FCR, VH, ET, TTAR of NT and EE, RW of carcass, blood concentration of TG (on d 40), TC (on d 22) and LDL (on d 22 and 40) values of the WN diet did not show a significant (p>0.05) difference compared to those of the C diet. Compared to those of the W diet, the WN diet showed the higher count of Lactobacilli and lower count of coliforms (p<0.01) and digesta viscosity (p<0.01). Conclusion: In general, the results of this study showed that Natuzyme Plus supplementation in a wheat-based diet can be appropriate to achieve a comparable growth performance in broiler chickens to those given the C diet probably through improving digesta viscosity, VH, ET, TTAR of NT and EE, $AME_n$, count of Lactobacilli and coliforms.

• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.63-68
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• 2016

어린잎 채소의 생산 및 가공 공정에서 원료농산물과 토양 및 용수 등 환경 시료를 채취하여 미생물학적 품질을 평가하고 식중독을 유발시킬 수 있는 주요 병원성 미생물을 분석하였다. 생산단계 어린잎 채소와 환경 시료의 일반 세균수는 모두 6.8 log CFU/g 이상 분석되었으며 대장균군은 어린잎 채소와 토양에서 각각 3.2 log CFU/g 및 3.5 log CFU/g 수준으로 오염되어 있었다. 가공공정 단계에서는 일반세균수와 대장균군 모두 세척공정이 진행됨에 따라 최종제품 단계에서는 오염수준이 감소되었다. B. cereus의 경우 생산단계에서는 어린잎 채소와 토양 또는 지지토에서 오염도가 높았으며, 가공공정에서는 원료 대비 최종 제품에서 약 1.4 log CFU/g 정도 감소되었다. 병원성 미생물의 정성분석 결과 생산단계에서는 S. aureus를 제외한 모든 병원성 미생물이 음성이었다. 본 연구에서 분리된 B. cereus를 이용하여 rep-PCR에 의한 유전적 상동성을 분석한 결과 생산단계의 경우 지지토와 시료에서 분리된 균주의 유전적 상동성이 높아 반복적으로 이용되는 지지토에 오염된 균주가 어린잎 채소로 이행되었을 가능성을 보여준 반면 가공공정에서 분리된 균주의 경우 유전적 상동성이 낮아 공정 중 재 오염될 가능성이 낮음을 시사하였다.

• 한국식품과학회지
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• 제30권6호
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• pp.1362-1366
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• 1998

전자가속기(electron accelerator)에서 발생되는 electron beam을 이용하여 인삼분말류에 대한 새로운 살균기법을 확보할 목적으로 시중에서 유통되고 있는 백삼 및 홍삼분말을 시료로 하여 그 살균효과를 감마선 조사법과 비교하였다. 백삼 및 홍삼 분말의 미생물 농도는 총세균이 $10^5\;CFU/g$ 수준이었고, 대장균군(coliforms)은 백삼분말에서는 시료 g당 $10^3\;CFU$ 수준으로 검출되었으나 홍삼분말에서는 음성으로 나타났다. Electron beam 조사에 따른 오염미생물의 살균효과는 호기성 총세균이 7.5 kGy, 곰팡이 및 대장균군이 2.5 kGy 이하의 조사선량으로써 미생물의 농도를 검출한계 이하로 살균시킬 수 있었고, 실온에서 4개월 간 저장후에도 미생물의 생육은 없었다. 초기 오염 총세균의 농도를 90% 사멸시키는데 필요한 조사선량($D_{10}$값), 즉 총세균의 방사선 감수성을 확인해 본 결과, 전자선은 $2.85{\sim}3.75\;kGy$, 감마선은 $2.33{\sim}2.44\;kGy$ 범위로 시료의 미생물 농도와 에너지의 종류에 따라 다소 다른 값을 나타내었으나 전자선은 감마선과 유사한 살균력을 나타내어 실용 가능성이 인정되었다.

• 한국식품과학회지
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• 제35권6호
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• pp.1237-1243
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• 2003

인삼 분말의 저장성을 증진시키기 위한 새로운 살균법으로서 고전압 상태에서 발생하는 코로나방전 처리법의 활용가능성을 평가하기 위하여 미생물살균효과, 이화학적 특성변화, 관능 특성을 비교?분석하였다. 코로나방전 처리한 인삼분말의 미생물 사멸효과를 살펴본 결과, 일반세균, 효모/곰팡이, 대장균군 모두 피크전압이 5 kv/cm 일 경우 미생물 사멸이 매우 미미하다가 피크 전압이 점차 증가할수록 비례적으로 사멸효과가 높아지는 결과를 볼 수 있었고, 피크전압 20 kv/cm의 코로나 방전 처리구에서 총 세균과 coliform은 약 95%, 효모/곰팡이는 약 99% 정도의 미생물 사멸효과를 나타내었다. 반면 코로나방전 처리한 인삼분말의 일반성분, 무기질, 유리당, 조사포닌, 색깔(Hunter's value) 모두 P<0.05 수준에서 유의적 차이를 보이지 않았다. 관능검사 역시 색깔특성, 향, 맛, 종합적 기호도 모든 측면에서 P<0.05 수준에서 유의적 차이를 보이지 않았다. 결론적으로, 코로나방전 처리는 인삼분말에서의 미생물 살균효과가 강하고, 영양소 파괴가 없으며, 관능적으로 무처리 인삼분말과 차이가 없는 것으로 밝혀져 기존의 방사선조사 처리 등 살균법을 대체할 수 있는 새로운 살균법으로서 활용 가능성이 높다고 판단된다.

• 한국식품저장유통학회지
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• 제18권1호
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• pp.98-102
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• 2011

본 연구에서는 이산화염소수를 이용한 계사 내 깔짚의 미생물 수 저감화를 통한 깔짚의 미생물학적 안전성 확보를 위하여 연구를 수행하였다. 사용하기 전의 깔짚에는 coliform, E. coli, Listeria spp., yeasts and molds 및 total aerobic bacteria가 높은 수준으로 검출되었으며 사용기간이 늘어남에 따라 미생물 수가 증가하였다. 500 ppm 이산화염소수를 이용한 살균처리에서는 coliform, E. coli, Listeria spp., yeasts and molds, total aerobic bacteria 및 Salmonella spp.의 균수가 모든 깔짚 시료에서 처리횟수에 따라 유의적으로 감소하였다. 사용하지 않은 깔짚에서는 coliform, E. coli, Listeria spp., yeasts and molds 및 total aerobic bacteria 수가 각각 4.47, 1.29, 1.23, 3.24 및 5.2 log CFU/g로 감소하였고, 1주 및 5주 사용한 깔짚의 경우도 모든 미생물 수가 현저하게 감소하였다. 따라서 본 연구 결과, 이산화염소수를 이용한 계사 내 깔짚의 미생물 수 저감화 방법이 도계된 계육의 미생물학적 안전성을 향상시키기 위한 방법으로 적합하다고 판단된다.

• 한국식품조리과학회지
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• 제24권1호
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• pp.99-105
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• 2008

Laver-wrapped rice and laver-wrapped rice containing a vinegar blend (vinegar:sugar:water:salt = 5:2:2:1) were prepared and their degrees of aging from 10 to $30^{\circ}C$, total cell numbers, and total coliforms were examined and compared. The total cell numbers of the laver-wrapped rice increased to 1 log cfu/g at 36 hours, and the total cell numbers of the laver-wrapped rice with vinegar had increased to within 48 hours. At $20^{\circ}C$ for 24 hrs, the total cell numbers for the laver-wrapped rice had increased to 5 log cfu/g: whereas trhe total cell numbers of the laver-wrapped rice with vinegar(5ml of vinegar marinade mixed into 100g of steamed rice), stored at the same conditions had not increased. In the vinegar-marinated rice (2ml/100g rice), microorganisms appeared at 18 hours. However, at the concentration of 5ml/l00g of rice, microorganisms were not observed at 24 hours. Coliforms did not appear in the laver-wrapped rice nor in the laver-wrapped rice with vinegar(prepared at 10ml/100g) until 48 hours. When stored at 10 and $20^{\circ}C$, no microorganisms were found in the laver-wrapped rice with vinegar until 48 hours, respectively. However, at $30^{\circ}C$, microorganisms were observed in the laver-wrapped rice from 24 hours, and from 48 hours in the laver-wrapped rice with vinegar. These results suggest that laver-wrapped rice should be consumed within one day. The number of microorganisms inside the laver-wrapped rice reached 6 log cfu/g by 24 hours, but the increase in the laver-wrapped rice with vinegar was slower. The aging(% damaged starch) of the laver-wrapped rice with vinegar(5ml/100g the rice) stored at $20^{\circ}C$ was reduced, with 3% damaged starch at 24 hours. Consumer evaluations revealed that the laver-wrapped rice prepared with 5ml of the vinegar blend received higher scores for flavor, taste, texture, and overall acceptance as compared to the control. In particular, significantly higher scores were given for taste, texture, and overall acceptability. In summary, the laver-wrapped rice with vinegar had an extended shelf-life(more than 1 day) at storage temperatures of $20-30^{\circ}C$, as well as reduced retrogradation. In addition, based on consumer evaluations, adding vinegar to laver-wrapped rice laver is effective for increasing overall acceptability.

• 한국수산과학회지
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• 제56권2호
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• pp.182-187
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• 2023

Fifteen samples of dried laver Pyropia tenera were collected from markets and processing plants in Korea for an assessment of their microbial and chemical hazards, in accordance with the Korean food code. The contamination levels of total viable bacteria, coliforms, Escherichia coli, and nine other pathogenic bacteria (Staphylococcus aureus, Salmonella spp., Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Enterohemorrhagic Escherichia coli, Yersinia enterocolitica, Bacillus cereus, and Campylobacter jejuni) were evaluated The concentrations of heavy metals (lead, cadmium, total mercury, and total arsenic) and radioactive isotopes (¹³¹I, and ¹³⁴Cs+¹³⁷Cs) in the laver samples were also determined. The total viable count of bacteria was 2.62±0.80 (1.48-4.45) CFU/g. The contamination levels of lead, cadmium, total mercury, and total arsenic were 0.024±0.005 (0.018-0.035), 0.090±0.038 (0.041-0.146), 0.008±0.005 (0.003-0.018) and 1.315±0.372 (0.814-1.930) mg/kg, respectively. All samples tested negative for significant levels of radioactivity, the nine pathogenic bacteria, coliforms, and E. coli (<1.00 CFU/g). We assume that ensuring the microbiological and chemical safety of dried laver can increase the demand for its exportation. The present study may serve as a basis for microbiological and chemical hazard assessment of dried lavers.