• 대한방사선방어학회:학술대회논문집
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• 2011.11a
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• pp.310-311
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• 2011

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.190-191
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• 2009

• 대한방사선방어학회:학술대회논문집
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• 2010.04a
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• pp.198-199
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• 2010

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.910-916
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• 2002

As the utilization of medicinal herbs in food and bio-industry increases, safe hygienic technologies for them are demanded. To consider the possibility of application of radiation technology for this purpose, the genotoxi-cological safety of three r -irradiated medicinal herbs were studied. Astragali Radix, Atractylodes Rhizoma and Cimicifugae Rhizoma were irradiated at 10 kGy, and then were extracted with hot water. The genotoxicity of the extracts was examined in two short-term in vitro tests: (1) Salmonella reversion assay (Ames test) in strains of TA98 and TA100; (2) Micronucleus test in cultured Chinese hamster ovary (CHO) cells. The extract was treated at maximum doses of 5 mg/plate in Salmonella reversion assay, and 1 mg/mL in micronucleus test where growth of CHO cells was inhibited by 50%. In Salmonella reversion assay with or without metabolic activation, both ex-tracts of irradiated and non-irradiated herbs showed no significant differences in formation of revertant colonies compared with the negative control. And also in micronucleus test, the incidences of micronucleus in CHO cells cultured with extracts of irradiated herbs were almost same as negative control in less than 3%. These results of two in vitro tests suggest that ${\gamma}$-irradiated herbs do not show mutagenicity and cytogenetic toxicity. Further tests of in vivo genotoxicity and chronic toxicity are needed to ascertain the safety of ${\gamma}$-irradiated herbs.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.7-12
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• 1999

The effects of antioxidants, ascorbyl palmitate (AP), ${\alpha}-tocopherol\;({\alpha}-Toc)$, BHA and ascorbyl $palmitate+{\alpha}-tocopherol\;(AP+{\alpha}-Toc)$ have been investigated on lipid peroxide formations in tallow immediately and during storage at $50^{\circ}C$ after gamma irradiation with the dose of $1{\sim}10kGy$. Immediately gamma irradiation greatly increased the initiative oxidation of tallow as was expected. But antioxidants were found to be greatly effective in minimizing the radiation-induced peroxidation of tallow and their antioxidative activities were $AP>BHA>AP+{\alpha}-Toc>{\alpha}-Toc$. Especially, AP showed greater antioxidative activity of initiate-oxidation than that of any other antioxidant. Oxidation of tallow during storage at $50^{\circ}C$ after irradiation induced the accelate of autoxidation. But the additions of antioxidants inhibited formation of peroxide. Their antioxidative activities were $BHA>AP+{\alpha}-Toc>{\alpha}-Toc>AP$. Especially $AP+{\alpha}-Toc$ mixture was not significantly different from BHA (p>0.05).

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.6-11
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• 2008

To check the microbiological safety with respect to increased virulence of surviving pathogens after irradiation, in this study, the transcriptional change of vvp gene encoding metalloprotease, which is one of the typical virulence factors of Vibrio mulnificus, was monitored by real-time PCR during the course of growth cycle after reinoculation of irradiated Vibrio. When V. vulnificus was exposed to a dose of 0.5 and 1 kGy, the lag period before growth resumption of sub-cultures became longer than non-irradiated counterpart as increase of irradiation dose. In the case of non-irradiated culture, the transcription of vvp was significantly activated at 15 h after inoculation, when bacterial growth reached the stationary phase, and the highest level of pretense activity (686 U/mL) was measured at the same time. Interestingly, vvp expression of irradiated Vibrio was turned up earlier than non-irradiated Vibrio during the mid log phase of growth, whereas these rapid induction of vvp expression from irradiated cells didn't result in an increase of metalloprotease production. When Vibrio was irradiated at 0.5 and 1 kGy, the protease activities peaked at 18 h after inoculation and the levels of activities were lower 1.2- and 1.4-fold, respectively, compared to the non-irradiated counterpart. Results from this study indicate that gamma radiation is not likely to activate the virulence ability of surviving Vibrio.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.3
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• pp.275-284
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• 2006

In the measurement of gamma rays emitted from the nuclide in the radioactive waste drum, to analyze the nuclide concentration accurately, it is necessary to use the proper calibration standards and to correct for the attenuation of the gamma rays. Two drums having a different density were used to analyze the nuclide concentration inside the drum in this study. After carrying out the system calibration, we measured the gamma rays emitted from the standard source inside the model drum with changing the distance between the drum and the detector. The measured values were corrected with the three kinds of gamma attenuation correction methode, as a results, the error was less than 10 % in the low density drum and less than 25 % in the high density drum. The measured activity in the short distance was more accruable than in the long distance. The transmission correction for the mass attenuation showed good results(very Low error) compared to the mean density and the differential peak correction method.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1050-1056
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• 1999

The effect of ${\gamma}-irradiation$ was investigated on salted and fermented squid, squid jeotkal. Squid jeotkal was prepared with salt concentrations of 5%, 10% and 20% and was fermented at $15^{\circ}C$ and $25^{\circ}C$ after ${\gamma}-irradiation$ with doses of 0, 2.5, 5 and 10 kGy, respectively. Proximate composition, salinity, water activity (Aw), pH, total bacteria and sensory evaluation were examined during fermentation periods. Results showed that ${\gamma}-irradiation$ had no effect on proximate composition, salinity and Aw compared with non-irradiated squid jeotkal. However, pH and total bacteria, as well as sensory evaluation, were changed variously with processing conditions such as NaCl concentration, irradiation dose and fermentation temperature. The results of total bacteria and sensory evaluation showed that squid jeotkal with NaCl concentration of 10% and an irradiation dose of 10 kGy maintained high quality for 30 days at $15^{\circ}C$. Therefore, it was considered that ${\gamma}-irradiation$ was effective in processing low-salted squid jeotkal and extending its shelf-life without adding any food additives.

• Journal of the Korean Society of Food Culture
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• v.19 no.5
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• pp.516-523
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• 2004

This study was conducted to investigate the changes in the qualify of gamma-irradiated seasoned cuttle during storage. Seasoned cuttle packed in PVC film (0.06 win) was stored at $15{\pm}1^{\circ}C$ for 6 months after treatment with doses of 0 to 7 kGy. Microbial populations of seasoned cuttle were $1.6{\times}10^{5}CFU/g$ in total aerobic bacteria, $10^{4}{\sim}10^{5}CFU/g$ in yeasts &molds, and negative in coliforms, which were effectively reduced by 3 kCy or higher up to the undetectable level(<20 CFU/g). The pH and moisture content of the samples were not changed with irradiation, but moisture was some decreased during storage. The instrumental color (especially Hunter b value), pigments (lipophilic &hydrophilic) and TBA value of the samples increased with storage time as well as irradiation dose more than 3 kGy. The influence of storage condition, however, were more significant. Irradiation did not induce any changes in volatile basic nitrogen (VBN) and trimethylamine (TMA) contents, thereby maintaining their contents lower than those of the non-irradiated samples during storage by reducing the microbial load.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.338-344
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• 2001

The effect of gamma-irradiation on the microbiological and general qualities of Kanjang (fermented soy sauce, Korean type) and Shoyu (fermented soy sauce, Japanese type) was studied. Samples were prepared, irradiated at 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for 18 weeks. The results showed that the Bacillus spp. was inactivated by 3 log cycles with the irradiation dose of 10 kGy and the number of Bacillus cells that survived from 10 to 20 kGy of gamma irradiation was decreased gradually during storage. Yeasts and Lactobacillus were nearly eliminated at 5 to 10 kGy of irradiation. The $D_{10}$ values of Bacillus, yeast and Lactobacillus in Shoyu were 2.67 kGy, 0.81 kGy and 1.30 kGy, in Kanjang were 2.75 kGy, 0.99 kGy and 1.47 kGy, respectively. The general quality of gamma irradiated Shoyu and Kanjang, such as total nitrogen, amino nitrogen, protease activity and pH were more stable than that of control during storage periods. Decolorization was observed just after irradiation, but the color was recovered during storage. The sensory evaluations showed that irradiated samples were more acceptable. Therefore, it was considered that gamma irradiation was effective for maintaining better quality of Shoyu and Kanjang during storage.