• Food Science and Preservation
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• v.9 no.1
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• pp.19-27
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• 2002

The effect of gamma irradiation was investigated on the microbiological and physicochemical qualities of boiled-dried anchovies (large- and smallsized) packed in PVC film (0.06 ㎜) during storage at 15$\pm$1$\^{C}$ for 6 months. On the other hand, thermoluminescence characteristics of minerals extracted from the sample were analyzed to evaluate its possibility in detecting the irradiated anchovies. The samples were contaminated by microbial levels of 104∼106 CFU/g in total aerobic bacterial counts and negative in coliforms, which were different depending on the sample sizes. Gamma irradiation at 3 kGy was effective for improving the hygienic quality of both samples for 6 months, keeping the microbial population less than 20 CFU/g. Besides it was not detrimental to the quality attributes, such as instrumental color parameters L, a, b, ΔE), browning, TBA value, volatile basic nitrogen, trimethylamine-N and sensory properties(appearance, color, odor, tape, overall acceptability). However, storage conditions (time, temperature, packing) showed a critical factor nfluencing the quality changes of dried anchovies. Thermoluminscence analysis was prove to distinguish irradiated from non-irradiated anchovies by comparing both temperature at which glow curves appear and the curve intensity, that was possible even after 6 months at - 20$\^{C}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.970-974
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• 2015

This study was designed to evaluate the therapeutic effect of quercetin against radiation-induced hepatocellular and hematopoiectic damage in BALB/c mice. Mice were exposed to 6 Gy of ${\gamma}$-radiation and orally administered quercetin (25, 50 mg/kg b.w.) for 7 consecutive days. ${\gamma}$-Irradiation caused marked elevation of serum aspartate aminotransferase and alanine aminotransferase, levels as well as reduction of spleen index, thymus index, and the number of white blood cells. In addition, ${\gamma}$-irradiation induced significant elevation of lipid peroxidation as well as reduction of antioxidant enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase. However, post-treatment with quercetin resulted in a significant recovery of all of these parameters. These results suggest that quercetin acts as a potent radioprotector against irradiation-induced cellular damage in mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.364-371
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• 2009

The effect of gamma irradiation ($0.5{\sim}2$ kGy) on the microbiological, physicochemical and sensory properties of peaches was investigated during 6 day storage at $20{\pm}3^{\circ}C$. Total aerobic bacteria, yeasts and molds significantly decreased with increasing dose level. In Hunter's color values, L-values decreased and a- and b-values increased with increment of irradiation dose level. Hardness significantly decreased with increment of irradiation dose level whereas pH, soluble solid, and total polyphenol contents increased with increment of irradiation dose level. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity of irradiated peach was higher than that of control and its activity increased with increment of irradiation dose level. Vitamin C content was not affected by irradiation. In sensory test, overall acceptabilities of irradiated samples were higher than those of control. These results suggest that gamma irradiation on peach was effective for microbiological safety while improving the antioxidant activity, but not good on color and texture of peach.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1619-1627
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• 1999

Microbiological characteristics of gamma irradiated low salt squid Jeot-gal were examined. Following the fermentation periods, total bacterial cell, Lactobacillus spp., Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and yeast cell number were counted on their selective media and some acid forming bacteria and Pseudomonas spp. were identified. As the gamma irradiation dose increased, the microbial density of early fermentation phase was reduced and the growth rate was delayed. The repression effects on microbiological growth by gamma irradiation were to be higher as salt concentration increased. Adequate conditions of salt concentration and gamma irradiation for low-salt squid Jeot-gal preparation were 10% and 10 kGy, respectively. Lactobacillus sp. 2, Micrococcus varians and Streptococcus sp. I were isolated from 5% salt containing squid Jeot-gal, and Micrococcus morrhuae was from 20% only while Lactobacillus plantarum and Lactobacillus brevis were widespread. Lactobacillus brevis, Pediococcus halophilus and Pseudomonas diminuta were sensitive and Lactobacillus plantarum, Micrococcus morrhuae and Pseudomonas sp. 3 were resistant to gamma irradiation. The diversity of microflora decreased as salt concentration decreased and gamma irradiation dose increased.

• KSBB Journal
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• v.23 no.6
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• pp.489-493
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• 2008

Although the seafood cooking drips were the byproducts from the fishery industry and being wasted, it had many nutrients including proteins. In this study, the effect of a gamma irradiation on the cooking drips from Hizikia fusiformis, Enteroctopus dofleni and Thunnus thynnus were investigated. The cooking drips were extracted with 70% ethanol solution, and the extracts were analysed for the protein concentration by three different methods of Lowry, BCA and Kjeldahl. The extracts were irradiated with different doses and the protein contents were compared with respect to the absorbed doses. Total content of the proteins was increased with increasing irradiation dose. The change of protein pattern in the irradiated cooking drips was also confirmed by SDS-PAGE analysis. These results shown that the proteins in cooking drips could be unfolded or aggregated by the irradiation. Therefore, gamma irradiation could be considered as an effective method for extracting useful proteins.

• Journal of Animal Science and Technology
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• v.49 no.4
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• pp.515-522
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• 2007

To develop the manufacturing method of ice cream with microbiologically safe and proper sensory quality using irradiation for sensitive consumer, 3 different flavors, which were resistant to their flavors against irradiation, were selected and used for ice cream manufacturing to reduce the irradiation-induced off-flavor problem. The general composition was not different among treatments. Total aerobic bacteria were detected as 2.38, 1.23, 1.38, and 1.15 log CFU/g level in ice cream with control(no flavor added), spearmint, mint, and citrus flavor, respectively. No viable cells were observed by irradiation at 1 kGy except for the control. Sensory evaluation indicated that the irradiated ice cream with spearmint flavor at 1 kGy and citrus flavor at 3 kGy had higher overall acceptability. Therefore, a low dose irradiation (less than 3 kGy) with mint or citrus flavors may enhance the safety of ice cream with proper sensory quality for sensitive consumer.

• Food Science and Preservation
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• v.15 no.5
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• pp.774-781
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• 2008

was performed and Staphylococcus sciuri, Bacillus cereus, Escherichia coli, Proteus mirabilis, and Enterococcus faecalis were identified. No Salmonella strain, a typical contaminant of eggs, was found. The radiation sensitivities of isolated bacteria and Salmonella typhimurium, in an inoculated model system, were expressed in $D_{10}$ values. The ranges of $D_{10}$ values shown by S. typhimurium, S. sciuri, B. cereus, E. coli, P. mirabilis, and E. faecalis were 0.365-0.399 kGy, 0.418-0.471 kGy, 1.075-1.119 kGy, 0.280-0.304 kGy, 1.132-1.330 kGy, and 0.993-1.290 kGy, respectively. The growth of all six test bacteria in eggs (inoculated at $10^6-10^7\;CFU/g$) during 3 days of post-irradiation storage at ambient conditions ($25^{\circ}C$) was recorded. S. typhimurium was eliminated by irradiation at 3 kGy, and E. coli and S. sciuri were eliminated by irradiation at 5 kGy. The viable cell counts of B. cereus, P. mirabilis, and E. faecalis in eggs showed 4-6 log reductions after irradiation with 5 kGy.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.849-856
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• 2020

In the gamma-ray energy spectrum study, nuclide analysis through energy analysis is very important. High-purity Ge detectors, which are commonly used for gamma-ray energy measurements, are commonly used because of their high energy resolution and relatively high detection efficiency. However, in order to maintain a high energy resolution, the semiconductor detector has a problem in that it is difficult to maintain the original performance if the noise generated from the surrounding environment is not effectively blocked, and the effect of the expensive device is not achieved. Therefore, in this study, ground loop isolator (NEXT-001HDGL) was used to remove the electrical noise generated from the detector. In order to test the effect of improving energy resolution, HPGe detection device newly installed in the proton accelerator KOMAC was used. In the case of gamma-ray energy 2614 keV, the energy resolution was improved from (0.16 ± 0.02) % to (0.11 ± 0.01) %, and in the case of gamma-ray energy 662 keV of 137Cs isotope, the energy resolution was improved from (0.72 ± 0.07) % to (0.27 ± 0.03) %. This result is considered to be very useful for the gamma ray spectrum study using the HPGe detection equipment of KOMAC(Korea Multi-Purpose Accelerator Complex).

• Journal of Radiation Protection and Research
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• v.34 no.4
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• pp.170-175
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• 2009

For the emergency radiation monitoring using gamma spectrometry, we should sufficiently survey the background spectra as environmental samples with systematic nuclide identification method. In this study, we obtained the gamma ray energy spectrum using a HPGe gamma spectrometry system from an air sample. And we identified nuclide of the gamma ray energy peaks in the spectrum using two methods -1) Half life calculation and 2) survey for cascade coincidence summing peaks using nuclear data. As the results, we produced the nuclide identification results for the air sample.

• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.65-68
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• 2006

In this study, the extent of plasmid DNA damage was observed according to concentration of BSH(Boron Sulfhydryl Hydride) and irradiation doses of neutron and ${\gamma}$-ray. The plasmid used was both pBR 322 (2870 bp) and ${\Phi}X174$ RF(5386 bp) DNA. Plasmid DNA damage by irradiation in the presence of BSH was analyzed by agarose gel electrophoresis. In the neutron experiment, DNA damage of both plasmid DNAs was increased according to increasing the concentration of BSH and neutron doses. But in the ${\gamma}$-ray experiment, there appeared no dose dependency as compared to the neutron experiment. The extent of the plasmid DNA damage in the presence of BSH was somewhat different according to irradiation by neutron or ${\gamma}$-ray.