• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.73-78
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• 1982

The optimal conditions of sterilization for Streptococcus pyogenes treated with disinfectant and antibiotics were investigated. The survivors of Streptococcus pyogenes had no effect at the concentration of 0.2% hydrogen peroxide but decreased abruptly when the concentration increased from 0.4% to 1.0% Minimum inhibitory concentration values of 0.78, 0.39 and 3.125 $\mu\textrm{g}$/$m\ell$ for erythromycin, tetracycline and cephalexin, respectively, were obtained for Streptococcus pyogenes when incubated at 37 $^{\circ}C$ for 24 hrs. Tetracycline and cephalexin showed bactericidal effect against Streptococcus pyogenes, whereas erythromycin did bacteriostatic effect.

• Microbiology and Biotechnology Letters
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• v.9 no.4
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• pp.231-236
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• 1981

Studies were made on the optimal conditions of sterilization for Streptococcus pyogenes treated with heat. The results were as follows: The optimal temperature on growth of Streptococcus pyogenes was 37$^{\circ}C$ and mean generation time was 20 minutes in the logarithmic growth phase. The suspension of Streptococcus pyogenes, adjusted to pH 6-9 and treated with heat at 5$0^{\circ}C$, showed logarithmic death rate. Specific death rate constant(k) values at pH 6-9 were 0.1448, 0.1194. 0.1273 and 0.1707 minute$^{-1}$ , respectively.

• Journal of Ginseng Research
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• v.18 no.2
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• pp.128-133
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• 1994

Color characteristics were investigated for white ginseng powder immediately and during storage following treatments of gamma ray or ethylene oxide (EO) for microbial decontamination. The variation in fatand water-soluble pigments of the sample was negligible immediately after both treatments, however an apparent increase was observed in the samples stored for four months at $25^{\circ}C$ and RH 90%, in the order of nontreated control, EO-fumigated, and 5 key-irradiated samples. Hunter's color a and b values of white ginseng powder increased slightly in proportion to irradiation doses, whereas EO fumigation caused a decrease in L value and an increase in a and b values of the sample, showing overall color difference (${\delta}^E$) of 1.8. Considering the higher ${\delta}^E$ in the higher RH conditions, airtight packaging and sterilization using like gamma ray were considered an effective means for maintaining high quality of color characteristics in stored white ginseng powder.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.309-325
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• 2024

The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

• Journal of Pharmaceutical Investigation
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• v.2 no.1
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• pp.58-62
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• 1972

The stabillities of taurine, niacinamide, and pyridoxine hydrochloride under exposure to ultra violet radiation in liquid preparations were studied. And sterilization effects for E. coli in both water and liquid preparations were also comparatively evaluated. The above mentioned organic compounds were stable under this experimental conditions and viable count of E. coli reveals that organic compounds dissolved in solution display protective action for microorganisms under UV-irradiation.

• Journal of Mushroom
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• v.19 no.3
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• pp.210-215
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• 2021

For sterilization of microorganisms of the Listeria genus contaminating enoki mushroom, pilot mushroom grower equipped with air sterilization devices were developed. Sterilization experiments were performed using physical and chemical treatments. Internal temperature and humidity were controlled, maintaining 6.62℃±0.30 in the upper shelves, 6.46℃±0.24 in the middle shelves, and 6.48℃±0.25 in the lower shelves. Humidities were 79.97%±4.42, 79.43%±4.06, and 79.94±4.30%, respectively, with a temperature setting of 6.5℃, and a relative humidity of 75%. A suitable enoki mushroom cultivation stage for air sterilizer application was during the growth stage, with temperature in the 6.5~8.5℃ range, and humidity of 70~80%. At these same internal conditions, the ozone concentration in the mushroom cultivator was found to be 160 ppb during ion-cluster generator operation. After physical sterilization, the Listeria innocua survival rate was 0.1 to 0.9% using ion cluster sterilization, and 9.3 to 10.6% using UV air sterilization. The Listeria innocua survival rates on different materials were 9.3~10.6% on the metal specimen, and 9.9~16.2% on the plastic wrapper. The survival rate was particularly high on the rough side of the plastic wrapper. Ion cluster air sterilization is a labor-saving and effective method for suppressing the occurrence of Listeria bacteria on mushroom growers walls and shelves. For the plastic wrapper, chemical sterilization is more effective than physical sterilization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.199-206
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• 2016

The aim of this study was to establish the optimal conditions to design a shoe rack that could effectively sterilize and deodorize shoes contaminated by various bacteria. The manufacture and evaluation of a shoe rock was conducted for one year from October 2014 to September 2015. The antibacterial efficacies were evaluated using Escherichia coli and Staphylococcus aureus by JIS Z 2801:2010. The deodorization efficiency was identified by the standard method for deodorization efficiency evaluation of an indoor air cleaner established by Korea Air Cleaning Association, SPS-KACA002-132:2006. The results showed that antibacterial evaluation showed more than 99.9% of the sterilization effects on Escherichia coli and Staphylococcus aureus after exposure to ultraviolet (UV) light for 30 seconds. The average deodorization efficiency for the test gases was 42.5%. The temperature in the shoes and in the shoe rack was lower than $40^{\circ}C$ and $25^{\circ}C$, respectively, when the UV lamp was turned on for 5 minutes and off for 25 minutes repeatedly. This was controlled by turning the UV lamp on and off to maintain the appropriate temperature in the shoes. In conclusion, the real deodorization efficiency is expected to be higher than the measured value because the internal volume of the shoe rack was smaller than the test chamber used to measure the deodorization efficiency. The deodorization effect could be increased further by the sterilization of bacteria causing bad odors in shoes. Further studies will be needed to determine the temperature deviations within the shoe rack to provide constant conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.148-152
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• 2013

An ultraviolet (UV) sterilization system was developed to decrease the number of microorganisms in filtered Acer mono sap (FAS). The Acer mono sap (AS) was passed through 18 strips of PTA fluoroplastic tubing with 30 UV lamps (total 1,170 W). During passage, the AS was effectively exposed to the UV rays. The total bacteria, coliform group and fungi were sterilized at a flow rate ranging from 852 to 1,358 mL/min and a UV power higher than 156 W. Although the sensory score of the UV-sterilized AS was significantly lower than that of the untreated AS, the sensory score was better under the condition of 390 W and 852~1,358 mL/min than under the other conditions examined. ANOVA did not reveal a significant difference in pH, total acidity, sugar content and color characteristic under all conditions tested (p<0.05). Considering the overall attributes of the AS quality, the optimum sterilization condition was determined to be 390 W and 852~1,358 mL/min.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• Journal of Korean Society of Archives and Records Management
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• v.1 no.1
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• pp.231-243
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• 2001

The sterilization method of records by fumigation using mixed gas of methyl bromide(MB) and ethylene oxide(ETO) has been generally used as a way to protect biological deterioration by microorganisms and insects. In this study, we confirmed sterilization effect of MB and ETO [86 : 14(Vol.%)] on and analyzed toxicity on microorganisms isolated from records. To analyze sterilization effect of fumigation on microorganisms and insect, we have fumigated microorganisms and insect with a various amounts mixed gas of MB and ETO, and various exposure time. Insect was sterilized at all experimental conditions. In microorganisms, sterilization effect was detected only when the mixed gas was treated at $120g/m^3$ concentration for at least 24 hrs. To test the possibility of isolated microorganisms as a threat to human health, it was investigated that toxicity test using yeast, radish and cancer cells on microorganisms. Only Aspergillus oryzae had an inhibition effect on growth of yeast. radish and cancer cells, respectively. These results demonstrate that sterilization effect can occur at low concentrations of the mixed gas on insect but requires higher concentrations of the mixed gas on microorganisms. In addition to, it is suspected that the possibility of the microorganism as a threat to human health is little.