• Journal of Dairy Science and Biotechnology
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• 제29권2호
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• pp.43-49
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• 2011

The increasing number of analytes in concern and the alarming health and environmental consequences have required effective means of monitoring for safety control. Biosensors offer advantages as alternatives to conventional analytical methods because of their inherent specificity, simplicity, and quick response. Colorimetric biosensor, one of biosensor group, is one of the easiest and the most convenient methods because detection can be done using naked eye. Recently, a novel method for rapid detection and read-out of specific immunoassays with naked eye using polydiacetylene (PDA) was developed. Polydiacetylene has recently been in the limelight as a transducing materials because of its special features that allow optical transduction of sensory signals and inherent simplicity and ease of use in supramolecular chemistry. Various forms of PDA are used as a sensor platform for detection of various biological analytes such as viruses, DNA, proteins, bacteria and hazardous molecules.

• Journal of Dairy Science and Biotechnology
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• 제32권2호
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• pp.105-109
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• 2014

Food borne pathogens are a growing concern for human health and food safety throughout the world. Milk and dairy products are commonly associated with spoilage or contamination from a wide variety of physical, microbial, and chemical hazards. Milk was inoculated with Staphylococcus aureus and stored at 5, 10, 15, 25, and $35^{\circ}C$ for 7 days, and we monitored the growth change and the variance of toxin production. The growth rate of S. aureus was suppressed in low temperature. We confirmed that growth rate and toxin production were accelerated when the storage temperature was increased. S. aureus began to produce toxins when the number of bacteria was higher than $10^5CFU/mL$. Therefore, managing the storage temperature of milk is important to inhibit the growth and the toxin production of S. aureus.

• Journal of Dairy Science and Biotechnology
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• 제32권2호
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• pp.101-104
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• 2014

Food safety is a global health goal, and food-borne disease are a significant public health threat throughout the world. Dairy products are susceptible to contamination through a wide variety of physical, microbial, and chemical hazards. Risks of microbiological hazards are of immediate and serious concern to human health. Milk was inoculated with Bacillus cereus and stored at 10, 15, 20, and $30^{\circ}C$ for 7 days. We monitored the effect of the temperature on growth rate and variance of toxin production. The growth rate of B. cereus was suppressed in low temperature. We confirmed that the growth rate and the toxin production were accelerated when the storage temperature was increased. B. cereus began to produce toxins when the number of bacteria was higher than $10^7CFU/mL$. Therefore, managing the storage temperature of milk is important to inhibit the growth and the toxin production of B. cereus.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.507-517
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• 2019

Rhodotorula is a group of pigment-producing yeasts well known for its intracellular biosynthesis of carotenoids such as ${\beta}-carotene$, ${\gamma}-carotene$, torulene and torularhodin. The great potential of carotenoids in applications in food and feed as well as in health products and cosmetics has generated a market value expected to reach over $2.0 billion by 2022. Due to growing public concern over food safety, the demand for natural carotenoids is rising, and this trend significantly encourages the use of microbial fermentation for natural carotenoid production. This review covers the biological properties of carotenoids and the most recent findings on the carotenoid biosynthetic pathway, as well as strategies for the metabolic engineering methods for the enhancement of carotenoid production by Rhodotorula. The practical approaches to improving carotenoid yields, which have been facilitated by advancements in strain work as well as the optimization of media and fermentation conditions, were summarized respectively.

• Microbiology and Biotechnology Letters
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• 제49권3호
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• pp.298-304
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• 2021

Photosynthetic conversion through cyanobacteria and microalgae is an increasingly serious concern in the global warming crisis. Many value-added substances are produced through strain improvement, and much research and development is being conducted to determine its potential as an actual industrial strain. Economic barriers throughout processing production can be overcome to produce value-added chemicals by microalgal strains. In this study, we engineered cyanobacteria strains for the photosynthetic production of squalene and confirmed the continuous cultivation of CO₂ and light conditions. The free-inducer system of gene expression was developed at the cyanobacterial strains. Then, the squalene production level and growth of the recombinant cyanobacteria were analyzed and discussed. For bio solar-cell factories, the ability to regulate genes based on the free-inducer gene expression system promotes metabolic engineering research and construction to produce value-added chemicals.

• Korean Journal of Community Nutrition
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• 제24권4호
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• pp.300-308
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• 2019

Objectives: This research was conducted to identify the consumers' food choice factors that affect the consumers' replacement of soft drinks with carbonated water. Methods: The present study used secondary data from a consumer panel survey conducted by the Rural Development Administration of Korea, and the data included the panel members' purchase records based on their monthly spending receipts. The survey asked the participants about their food choice factors and their personal responsibility for their health. This survey included independent variables for the consumers' food purchase factors. As a dependent variable, two types of groups were defined. The replacement group included those people who increased their purchase of carbonated water and decreased their purchase of soft drinks. The non-replacement group included those people who did not change their purchase patterns or they increased their purchase of soft drinks and they decreased their purchase of carbonated water. Logistic regression analysis was conducted to determine the consumers' food choice factors that were associated with replacing soft drinks with carbonated water. Results: The replacement group was significantly associated with (1) a younger age (OR=0.953), (2) being a housewife (OR=2.03), (3) higher income (OR=1.001) and (4) less concern about price (OR=0.819) when purchasing food. This group also showed (5) higher enjoyment (OR=1.328) when choosing food and (6) they took greater responsibly for their personal health (OR=1.233). Conclusions: This research is the first study to mainly focus on soft drinks and carbonated water. The result of this research showed that young, health-conscious consumers with a higher income and who are more interested in food have more possibilities to replace soft drinks with carbonated water. These research findings may be applied to consumers who have characteristics that are similar to the young health-conscious consumers and the results can help to suggest ways to reduce sugar intake and improve public health. However, this research has a limitation due to the application of secondary data. Therefore, a future study is needed to develop detailed survey questions about food choice factors and to extend these factors to all beverages, including soft drinks made with sugar substitutes, so as to reflect the growth of alternative industries that use artificial sweeteners or different types of sugar to make commercially available drinks.

• Korean Journal of Community Nutrition
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• 제24권2호
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• pp.137-151
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• 2019

Objectives: The rapidly changing dietary environment requires a study that addresses the status of middle and high school students regarding their consumption of convenience food sold at convenience stores. Methods: This study examined adolescents' lifestyle patterns, dietary habits, and status of consuming convenience food at convenience stores. A total of 659 students (329 middle school students and 330 high school students) in Incheon participated in this questionnaire survey. Results: The mean age of the subjects was 13.7 years for the middle school students, and 16.6 years for the high school students. The gender and grade distributions in the middle and high school students were similar. The middle school students reported that they spent more time using electronic devices (p<0.001) or watching TV (p<0.001) than high school students. More than 60% of middle and high school students consumed convenience food at convenience stores without statistical difference between the two groups. The main reason for consuming convenience food from convenience stores was its convenience followed by taste in both groups. Despite the high frequency of consuming convenience food, the students rarely checked the nutrition labels at the time of purchase. On the other hand, they were still most concerned about the nutritional value of the convenience foods when they consumed convenience foods. The most frequently consumed convenience food was ramyon in both groups. Significant positive correlations were observed between the frequency of consuming convenience food at convenience stores and lifestyle factors for the middle school students, including monthly allowance, time for using electronic devices, and number of private lessons. For the high school students, however, the only monthly allowance had a significant positive correlation with the consumption. Conclusions: Adolescents are increasingly exposed to convenience foods and relevant nutritional issues are a concern. Therefore, a dietary environment that is adequately formed for the healthy development of youth as well as systematic nutrient education that is appropriately designed for both middle and high school students is required.

• The Korean Journal of Physiology and Pharmacology
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• 제27권3호
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• pp.267-275
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• 2023

Cardiotoxicity, particularly drug-induced Torsades de Pointes (TdP), is a concern in drug safety assessment. The recent establishment of human induced pluripotent stem cell-derived cardiomyocytes (human iPSC-CMs) has become an attractive human-based platform for predicting cardiotoxicity. Moreover, electrophysiological assessment of multiple cardiac ion channel blocks is emerging as an important parameter to recapitulate proarrhythmic cardiotoxicity. Therefore, we aimed to establish a novel in vitro multiple cardiac ion channel screening-based method using human iPSC-CMs to predict the drug-induced arrhythmogenic risk. To explain the cellular mechanisms underlying the cardiotoxicity of three representative TdP high- (sotalol), intermediate- (chlorpromazine), and low-risk (mexiletine) drugs, and their effects on the cardiac action potential (AP) waveform and voltage-gated ion channels were explored using human iPSC-CMs. In a proof-of-principle experiment, we investigated the effects of cardioactive channel inhibitors on the electrophysiological profile of human iPSC-CMs before evaluating the cardiotoxicity of these drugs. In human iPSC-CMs, sotalol prolonged the AP duration and reduced the total amplitude (TA) via selective inhibition of I_Kr and I_Na currents, which are associated with an increased risk of ventricular tachycardia TdP. In contrast, chlorpromazine did not affect the TA; however, it slightly increased AP duration via balanced inhibition of I_Kr and I_Ca currents. Moreover, mexiletine did not affect the TA, yet slightly reduced the AP duration via dominant inhibition of I_Ca currents, which are associated with a decreased risk of ventricular tachycardia TdP. Based on these results, we suggest that human iPSC-CMs can be extended to other preclinical protocols and can supplement drug safety assessments.

• The Journal of Fisheries Business Administration
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• 제38권2호
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• pp.25-40
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• 2007

Recently, fisheries safety has been a matter of primary concern among consumers and suppliers. This phenomenon made them require the introduction of fisheries traceability systems. For traceability systems to be effective, automatic identification means play an important role. Therefore, RFID-based fisheries traceability systems are more required than barcode-based fisheries traceability systems. Unlikely EU and Japan, Korea did not accept mandatory traceability regulations. But Many countries began to accept mandatory traceability regulations to diminish food risks. So Korea is expected to adopt them in the near future. The purpose of this study is to find what benefits are generated from the adoption of RFID-based fisheries traceability systems and are related to their success. To do these, this study investigated primary benefits of RFID-based fisheries traceability systems from the perspectives of consumers and suppliers. Consumers' benefits were derived from the perceived risk dimensions. And suppliers' benefits were derived from operational benefits of RFID systems. To purify the benefits from RFID-based fisheries traceability systems, reliability and factor analysis were used. And the refined benefits of RFID-based fisheries traceability systems were additionally analyzed to find which benefits were significantly related to fisheries traceability systems' success. According to the analysis results, all risk dimensions except social risk were significantly related to their success. But in the benefits of suppliers, only "recalls and counterfeits" factor was significantly related to their success. These results implied that fisheries traceability systems should be based RFID technology instead of barcode and fisheries traceability systems were related to almost food risk dimensions. It's because these significant factors are related all food risks except social risk and the benefits of suppliers can be derived from only RFID technology.

• Journal of Nutrition and Health
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• 제37권1호
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• pp.38-44
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• 2004

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades and concerns about naturally occurring harmful contaminants of food. Although, irradiation provides an excellent safeguard for the consumer by destroying harmful bacteria, it would be necessary to investigate nutritional adequacy of irradiated foods with a special emphasis on such foods as red pepper powders, cold-water fishes (mackerel), sesame seeds that are widely consumed in Korea. These food items are of special concern due to the fact that most of them are imported and that several nutrients contained in them are sensitively reacting to irradiation. We observed changes in the antioxidant nutrients contents, such as vitamin A, $\beta$-carotene, vitamin C and total phenol, and also vitamin B$_1$ in the foods that were irradiated at different dose levels. The nutrients contents in red pepper were respectively 98.6% and 92.3％ for total phenol, and 97.8% and 94.5% for $\beta$-carotene, right after irradiation at the dose of 10 and 20 kGy. The vitamin C contents decreased with irradiation doses up to 76.4% (10 kGy) and 68.5% (20 kGy) and B$_1$ contents decreased to 54.9% and 80.7% of non irradiated red pepper. When the mackerel was irradiated at the applied dose of 3 and 7 kGy, total phenol concentration of the irradiated fish was respectively 91.3% and 94.2% of non irradiated fish. The amounts of vitamin A were 82.6% (3 kGy) and 78.0% (7 kGy) of unirradiated sample and vitamin B$_1$ contents reduced to 30.5% and 51.5%. $\alpha$-Tocopherol content was 33.9% of the non-irradiated one when it was irradiated at 7 kGy. Vitamin A and ${\gamma}$-tocopherol contents in sesame seeds linearly decreased with the applied doses (5 and 10 kGy) Vitamin A contents decreased up to 87.8% (5 kGy) and 82.9% (10 kGy) and that of ${\gamma}$-tocopherol were 72.4% and 66.5% of the unirradiated sample.