본 연구에서는 소양인, 태음인 그리고 소음인 지원자의 혈액으로부터 분리한 면역세포에서 한국, 일본 및 미국에서 재배한 생마늘(RG)과 증숙마늘(SG) 70% 에탄올추출물에 대한 면역활성과 항산화능을 탐색하였다. 70% 생마늘추출물(RGE)은 세포 증식율, NO와 TNF-α 생성능이 소음인에 가장 높았고, 태음인과 소양인 순으로 나타났다. 반면에, 증숙마늘 추출물(SGE)은 각 개인별 체질에 영향을 미치지 않으면서 생마늘 추출물보다 면역활성이 더 높았다. 뿐만 아니라 국가별로 재배한 생마늘 및 증숙마늘의 면역효능은 나라별로 차이가 있었으며 한국산이 가장 높은 면역활성을 나타내었고 일본산, 미국산 순으로 나타났다. 이러한 결과는 항산화 효능에서도 유사한 경향을 나타내었다.
In this study, the transfer rate of wild type Listeria monocytogenes (LM) was investigated to establish the standard of safety management during pork meat processing for meat to meat and meat to food contact surfaces contamination at 5 and 10oC. The transfer rate of LM from meat to meat during the processing increased from 0.02% after 30 min to 0.42% after 120 min at 5oC, while for conveyor belt and stainless steel, it decreased from 0.015% and 0.013% after 30 min to 0.002% and 0.0003% after 120 min at 5oC, respectively (p < 0.05). When temperature increased to 10oC, the transfer rates of LM from meat to meat, conveyor belt and stainless steel were the highest at 60 min exposure, and all decreased after 120 min. In reverse, the transfer rate from food contact surface to pork meat was significantly higher than that from pork meat to food contact surface (p < 0.01). Also, the transfer rate to conveyor belt was significantly higher than stainless steel (p < 0.05) and it was highest at 30 min exposure time in both 5 and 10oC. This study indicates that the transfer and adherence rates of LM are influenced by the contact time and temperature. Consequently, these results were utilized to develop a predictive model with a high level of confidence which can lead to prevent cross-contamination during pork meat processing.
The purpose of this study was to evaluate microbiological contamination of fresh-cut produce salads and raw cabbage toward climate change. Total aerobic bacteria, coliform and Escherichia coli were monitored to get the contamination levels and E. coli O157:H7, Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes and Salmonella spp. to detect pathogens with risk of foodborne disease from samples. Collection of 360 samples (180 fresh-cut produce salads and 180 raw cabbage), including 60 samples from each area after setting 3 areas depending on annual temperature and annual rainfall. As a result, total aerobic bacteria and coliform group were different was performed areas in raw cabbage but there was no difference between areas in fresh-cut produce salads. In addition foodborne pathogens including E. coli were not isolated from fresh-cut produce salads.
본 연구는 probiotics 균주 선발을 위해 동치미로부터 식중독균에 대해 높은 항균활성을 보이는 유산균을 분리동정하여 배양조건을 확립하고, 위산, 담즙산, 췌장액에 대한 저항성 실험을 비교, 분석하여 probiotics 균주로 사용 가능성을 탐색하고자 하였다. 2% CaCO3를 첨가한 MRS agar를 이용하여 김치 무리로부터 식중독균의 저해능이 우수한 8 균주를 분리하였다. 식중독균에 대해 항균활성실험 결과 J4가 B. cereus는 19.85±0.53 mm, L. monocytogenes는 18.37±0.38 mm, S. aureus는 22.49±0.37 mm, E. coli는 17.90±0.64 mm, S. enterica는 16.28±0.53 mm, V. parahaemolyticus는 24.59±0.29 mm의 생육저해환을 형성하여 가장 높은 항균력을 나타내었다. J4 균주의 16S rDNA 염기서열을 분석한 결과 L. sakei와 99% 상동성을 나타내어 L. sakei J4라 명명하였다. L. sakei J4의 최적배양조건은 pH 8.5, 30, 정치배양시 가장 활발하게 생육이 진행됨을 확인하였다. L. sakei J4는 인공위액에서의 생존율 24.3±3.0%, 담즙산에서의 생존율 25.8±0.4%, 췌장액에서의 생존율 101.2±4.5%로 다른 균주보다 상대적으로 생존율이 높았으며, 향후 alginate를 이용한 캡슐화, chitosan을 이용한 재코팅 등의 연구방법을 정립하여 인공위액에 대한 저항성을 높인다면 프로바이오틱스 균주로서 조건을 충족시킬 수 있으리라 사료된다.
This study was performed to determine the transfer rates of each foodborne pathogen from pork meat packaging during the processing. We analyzed the transfer rate of Listeria monocytogenes from contaminated pork meat to worker's hands (wearing polyethylene gloves, PEG; cotton gloves, CG; and bare hands), cutting boards and knives, and vice versa. Transfer rate of CG 100.00% was higher than that of bare hands 2.513% and PEG 1.511%. In particular, when wearing CG, the transfer rate from the CG to bare hands with CG was 0.08%. Also, the range of transfer rates from contaminated pork meat to cutting board and knife was 0.352-3.791%. In contrast, transfer rates from the workers’ hands (with PEG/CG and bare hands) to cutting board, knife, and pork meat ranged from 0.001 to 0.141%. There was a lower transfer rate from workers’ hands than from pork meat. These findings indicate that use of PEG could effectively reduce or prevent the cross-contamination compared to CG and provide important information concerning the consecutive transfer of L. monocytogenes during food processing.
목포항 주변 해역의 6개 정점에서 1997년부터 2004년까지 수질의 계절 및 년간 변동에 대해 조사하였다. 염분, pH, 용존무기질소와 용존무기인은 년간 다양하게 나타났다. 염분은 1998년에 유의하게 나타났으나, 영양염 농도들은 1998년이 다른 년도보다 유의하게 높았다. 수온, DO, COD와 DIP의 농도는 계절 변동이 명확하게 나타났으며, 이러한 계절적인 변화는 영산강하구언에서 유입되는 담수의 계절적인 특징에 영향을 받았다. 수온, COD와 DIP는 8월에 유의하게 높았으나, 염분과 DO는 8월에 최소로 나타났다. 정점 1(영산강 하구언)의 수질은 영산강의 유입에 따른 낮은 염분과 높은 영양염의 특성을 보였으나, 정점 6(목포항 외해)은 주로의 외해의 특성을 보였다. 목포항 주변 해역에서 수질 인자간의 관계에서 염분은 COD, DO, pH, Chlorophyll a와 영양염 농도에 주요한 요인으로 나타났다.
The Electron/Hole Pair is generated when the activation energy produced by ultraviolet ray illuminates to the semiconductor and OH- ion produced by water photocleavage reacts with positive Hole. As a results, OH radical acting as strong oxidant is generated and then Photocatalytic oxidation reaction occurs. The photocatalytic oxidation can oxidate the non-degradable and hazardous organic substances such as pesticides and aromatic materials easier, safer and shorter than conventional water treatment process. So in this study, many factors influencing the oxidation of chlorophenols, such as inorganic electrolytes addition, change of oxygen and nitrogen atmosphere, temperature, pH, oxygen concentration, chlorophenol concentration, were throughly examined. According to the experiments observations, it is founded that the rate of chlorophenol oxidation follows a first-order reaction and the modified Langmuir-Hinshelwood relationship. And the photocatalytic oxidation occurs only when activation energy acting as Electron/Hole generation, oxygen acting as electron acceptor to prevent Electron/Hole recombination, $TiO_2$ powder acting as photocatalyst are present. The effects of variation of dissolved oxygen concentration, temperature and inorganic electrolytes concentration on 2-chlorophenol oxidation are negligible. And the lower the organic concentration, the higher the oxidation efficiency becomes. Therefore, the photocatalytic oxidation is much effective to oxidation of hazardous substances at very low concentration. The oxidation is effective in the range of 0.1 g/L-10 g/L of $TiO_2$. Finally when the ultra-violet ray is illuminated to $TiO_2$, the surface characteristics of $TiO_2$ change and Adsorption/Desorption reaction on $TiO_2$ surface occurs.
The occurrence of objectionable tastes and odors in drinking water is a common and widespread problem. The most troublesome odors are usually those described as muddy or earthy-musty. Two organic compounds which have been implicated as the cause of earthy-musty odor problems in water are geosmin and 2-Methylisoborneol. These earthy-musty organics have been shown to be metabolites of actinomycetes and blue green algae. The purpose of this paper is to describe adsorbability in removing these two oder causing compounds(geosmin and 2-MIB) upon various conditions like pH variation, adding humic acid and different activated carbon. The conclusion of this study are as followings. In batch test, carbon dosage is 10mg/100ml for geosmin and 15mg/100ml for 2-MIB. Both were in equilibrium state after 60 hours. In model simulation, F-P model described experiment data and modelling data appropriately in geosmin but F-S model not. In case of 2-MIB, models didn't describe relation between experiment and modelling data well. Two causative agents of earthy-musty odor compounds, geosmin and 2-MIB, are strongly adsorbed by activated carbon either coconut or brown. There appears to be no effect of pH (3,7,9) on adsorption of these two organics. Activated carbon proved to be more effective for removing geosmin than for removing 2-MIB. When activated carbon is. used in removing these two organics, the removal of these appeared to be adversely affected by back ground organic compounds, such as humic substances, due to competitive adsorption.
It is well known that the adsorption character of activated carbon is dependent on the specific surface area and pore volume, but the relationship between the surface-chemical structure and the adsorption character has not been studied very often. The purpose of this study is to investigate the effect of the acidic surface functional groups of activated carbon and the adsorption characteristics of low concentration phenol. So three types of activated carbons and four different treatments were introduced to this isotherm experiment. These treatments were nontreatment, 1N $HNO_3$ treatment, 6N $HNO_3$ treatment, $H_2O_2$ treatment. The conclusions of this study are as followings. If the initial concentration of phenol is high as 5mg/l, the adsorption is dependent on the specific surface area. If the initial concentration of phenol is low as $100{\mu}g/l$, the adsorption is dependent on the average pore volume. The acidic surface functional groups prevent the adsorption of phenol molecules to activated carbon. And the adsorbed amount decreases more for $HNO_3$ treatment than for $H_2O_2$ treatment and more for concentrated $HNO_3$ treatment than for dilute $HNO_3$ treatment.
An experimental study was conducted to investigate the effects of chlorine dioxide and ozone on reduction of THM(trihalomethane) formation. Precursor concentration, chlorine concentration, reaction time, pH, and temperature were governing compornents of THM formation. When other conditions are constant, THM formation increased linearly with precursor concentration increased. THM formation increased when pH increased from 5 to 9. In combined treatment with chlorine and chlorine dioxide, chlorine treatment after chlorine dioxide treatment made less THM than any other case does. Ozonation reduced THMFP(THM formation potential) of THM precursor. THMFP decreased exponentially with reaction time increased. Also biodegradability of humic acid was enhanced by ozonation.
Long-term trends and distribution patterns of water quality were investigated in the Cheonsu Bay of Korea from 1983 to 2004. Water samples were collected at 4 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO) and nutrients. Spatial distribution patterns were not clear between stations but the seasonal variations were distinctive except COD, SS and nitrate. Twenty two year long-term trend analysis by PCA revealed the significant changes in water quality in the study area. Water quality during 1980's and early 1990's showed high SS, low nutrients and low COD which increased during the mid and late 1990's and early 2000's. Overall water quality in the Cheonsu Bay indicated the increase in nutrients and COD concentration.