• Journal of Radiation Industry
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• v.6 no.4
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• pp.299-304
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• 2012

The quality properties of freeze-dried apples, pears, strawberries and pineapples gamma-irradiated at 0, 1, 2, 3, 4, and 5 kGy were evaluated to develop germ-free products for immuno-compromised patients. The initial count of total aerobic bacteria in non-irradiated apples, pears, strawberries and pineapple was 2.5, 3.1, 2.6, and $3.2{\log}\;CFU{\cdot}g^{-1}$, respectively. Microorganisms were not observed in apples after 1 kGy, in pears and strawberries after 4 kGy, and in pineapples at 5 kGy within a detection limit of $10{\log}\;CFU{\cdot}g^{-1}$. In addition, the sterilization of each sample was confirmed at the same dose. The score for the overall acceptance of freeze-dried fruit irradiated at a sterilization dose was 5.5 for apples, 4.1 for pineapples, and 4.0 for the other fruits, whereas that of non-irradiated control sample was 5.6 for apples, 5.2 for pears, and 5.8 for strawberries and pineapples with a 7-point scale. As a result, gamma irradiation of 1 kGy for apples, 4 kGy for strawberries and pears, and 5 kGy for pineapples is sufficient to sterilize each freeze-dried fruit with acceptable sensory properties.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1362-1366
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• 1998

The sterilizing effect of electron beam was compared with that of gamma irradiation for commercial ginseng powders. White and red ginseng powders were contaminated by about $10^5\;CFU/g$ of total bacteria and by $10^3\;CFU$ of coliforms only in white ginseng powder. Data of microbial population for the sterilizing effect of electron beam irradiation showed that no microorganisms were detected in the samples irradiated up to 7.5 kGy for total aerobic bacteria and 2.5 kGy for molds and coliforms. Such doses were effective for controlling the microbial growth in the samples during 4 months of storage at room temperature. Decimal reduction doses $(D_{10}$ value) on the initial bacterial populations were $2.85{\sim}3.75\;kGy$ in electron beam and $2.33{\sim}2.44\;kGy$ in gamma irradiation, which were influenced by the initial microbial loads and the energy applied. Compared with gamma irradiation, electron beam showed a similar result in its sterilizing effect on ginseng powders, suggesting its potential utilization in due time.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.136-140
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• 1982

In order to evaluate the feasibility for the sterilization of Korean red and white ginseng powder by irradiation, red and white ginseng powder (120 mesh) was irradiated by 0.1, 0.3, 0.5, 0.7, 1.0 and 2.0 Mrad with $^{60}Co$ irradiator (dose rate: 4000 rad/h). Extraction rate of crude saponins by buthanol and by 50% ethanol were slightly increased according to the irradiation dose (buthanol ex. 1.7%, 50% ethanol ex. 2.6% at 1.0 Mrad irradiation. There are no remarkable changes in HPLC patterns of crude saponins by radiation. It was found that irradiation up to 1 Mrad on Korean ginseng products have no significant effect on proximate component, reducing sugar and amino nitrogen of ginseng powder and on the color density of ginseng extract with 50% ethanol. Irradiation up to 1 Mrad could be utilized for the sterilization of Korean ginseng powder whithout changes of physicochemical properties.

• Food Science and Preservation
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• v.13 no.5
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• pp.531-537
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• 2006

This study was conducted to evaluate the combined effect of heating and gamma irradiation on the shelf-stability and quality of kimchi during storage at $35^{\circ}C$. The optimum condition for heat treatment of kimchi was considered at $60^{\circ}C$ for 30 min. Irradiation after kent treatment was effective to inhibit the growth of microorganisms and prevent the quality change of kimchi during storage. In particular, microorganisms of kimchi co-treated with heat and 20 kGy-irradiation were not detected and sensory scores of that were the highest after storage at $35^{\circ}C$ for 14 days. Therefore, combination treatment of heat and irradiation was considered as the effective method to improve the shelf-stability of kimchi in the accelerated condition.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.112-118
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• 1988

The effect of gamma irradiation of microbiological and physicochemical properties of raw ingredients (thirteen kinds of protein sources) for the mixed feed were investigated. The total aerobic bacteria counts in the samples was ranged from $10^2$ to $10^7$cells/g. After 5 to 7 kGy irradiation, the total count was reduced by 3 to 4 log cycles. Coliforms were detected in seven samples and the range was from $10^4$ to $10^6$cells/g. Enteric pathogens were found only in fish meal and poultry byproduct as $10^2$ to $10^6$cells/g. They were sensitive to radiation and completely sterilized by 3 to 5 kGy irradiation. Total fungi count was ranged from $10^1$ to $10^4$cells/g in all samples. They were osmophiles such as Aspergillus, Penicillium, Cladosporium, Aureobasidium and Rhizopus and were destroyed by 3 to 7 kGy irradiation. Five species of potential mycotoxin producers including Aspergillus flavus were also identified. Physicochemical properties, such as total amino acid content, TBA value, POV and color difference showed that irradiation with optimum does was less detrimental than autoclaving.

• Food Science of Animal Resources
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• v.35 no.3
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• pp.293-298
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• 2015

Porcine placenta extract (PPE) is known to possess anti-inflammatory properties owing to its high concentration of bioactive substances. However, the need to eliminate blood-borne infectious agents while maintaining biological efficacy raises concerns about the optimal method for sterilizing PPE. Therefore, the objective of this study was to compare the effects of the standard pressurized heat (autoclaving) method of sterilization with γ-irradiation on the anti-inflammatory effects of PPE. The anti-inflammatory actions of these two preparations of PPE were evaluated by measuring their inhibitory effects on the production of NO, the expression of iNOS protein, and the expression of iNOS, COX2, TNF-α, IL-1β, and IL-6 mRNA in lipopolysaccharide-stimulated RAW 264.7 cells. Compared with autoclaved PPE, γ-irradiated PPE showed significantly greater inhibition of NO production and iNOS protein expression, and produced a greater reduction in the expression of iNOS, COX2, TNF-α, IL-1β, and IL-6 mRNA. These results provide evidence that the sterilization process is crucial in determining the biological activity of PPE, especially its anti-inflammatory activity. Collectively, our data suggest that γ-irradiated PPE acts at the transcriptional level to effectively and potently suppresses the production of NO and the expression of pro-inflammatory cytokines.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.326-336
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• 1997

Four ice nucleation-active bacteria (INA-bacteria), Pseudomonas syringae, Xanthomonas campestris, Escherichia coli JM109/pEIN229 and Gluconobacter oxydans/pKIN230, were treated with heat, pressure and gamma-irradiation to compare viability and their ice nucleation activity (INA) after sterilization. Gamma-irradiated INA-bacteria showed the least decrease in T90 value (the temperature at which the 90% of drops are frozen). According to cumulative INA spectra, gamma-irradiated INA-bacteria showed little decrease in class A ice nuclei $(nucleate\;H_{2}O\;at\;higher\;than\;-5^{\circ}C)$, pressurized INA-bacteria showed more than 90% decrease in class A ice nuclei, and heat-treated INA-bacteria barely showed class A ice nuclei. Differential scanning calorimetry (DSC) was used to examine the effect of INA-bacteria on the thermophysical properties of water at freezing temperature. Freezing peaks were appeared at about $11{\sim}15^{\circ}C$ higher on thermograms and enthalpies of phase change were decreased for the water containing INA-bacteria compared with the pure water, while melting peaks were not shifted. INA measured by DSC method were significantly correlated with INA measured by drop freezing method $(R^{2}>0.993,\;p<0.0001)$, indicating that DSC can be used as a new, simple and precise method for measuring INA.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.205-212
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• 2020

Foodborne diseases occur frequently and have various being related to the intake of contaminated foods. Seafood products are susceptible to contamination due to higher water content and microorganisms, which combine to give them a short shelf-life. Various approaches have been applied to overcome this problem. Edible coatings that are also biodegradable and biocompatible have been discussed as one of the applicable solutions. These coatings can actually help to maintain seafood quality by inhibiting the growth of microorganisms and delaying the loss of moisture. This paper presents the effects of various natural bio-polymers, antimicrobial substances and physical sterilization techniques such as gamma irradiation, ultraviolet (UV) sterilization, and light-emitting diode (LED) sterilization on seafood coatings.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.43-51
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• 2008

Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.191-196
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• 2011

The economic scale of nuclear application is a good indicator to show how the radiation technology is useful and contribute to improve public welfare and living standard. Recent research in Japan shows that the economic scale of nuclear field was 4,112 B¥ for radiation application(46%) and 4,741 B¥ for nuclear energy (54%) playing a role of "two wheels of one cart" in nuclear field and the total 8,853 B¥ constitutes 1.8% of gross domestic products (GDP). The radiation application consisted of 2,295 B¥ (56%) in industry (semiconductor, sterilization, nondestructive testing, radiation processing of tires, etc.), 1,538 B¥ (37%) in medicine (therapy and diagnosis such as X-ray, nuclear medicine, computed tomography, etc.) and 279 B¥ (7%) in agriculture (mutation breeding, food irradiation, sterile insect technique, etc.). Radiation application by ${\gamma}$-ray, electron beam and ion beam is steadily increasing in Japan.