• Journal of Radiation Industry
• /
• v.17 no.4
• /
• pp.533-542
• /
• 2023

We developed an emergency national manual for preservation of cultural heritage using irradiation disinfection technic under flood disaster. And we examined its practicality with a critical radiation dose on fungi that occur at water-logged event in order to prevent fungal damage that occurs during submersion. The X-ray irradiation for this experiment was conducted at the Production Technology Research Institute located in Yeongcheon, Gyeongsangbuk-do. A disinfection critical dose of 12 kGy was selected for two types of fungi known to spread rapidly and are resistant to radiation to submerged cultural properties, and this experiments were conducted by setting a target dose of 12kGy at 8.37mA at 5MeV. Under the above conditions, only continuity of irradiated samples were completely disinfected. This suggests that continuity of irradiation is important for fungal disinfection.

• The Plant Pathology Journal
• /
• v.32 no.2
• /
• pp.157-161
• /
• 2016

Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika.

• Journal of Radiation Industry
• /
• v.4 no.1
• /
• pp.73-77
• /
• 2010

In recent day, there is much interest in the biocidal activity of silver since silver is known to be safe and effective as disinifectant and biocidal material against coliforms and viruses. In this study, hydrogels containing silver acetate as antibacterial agent have been prepared using gamma rays irradiation. The hydrogels are composed of poly(vinyl pyrrolidone) (PVP), poly(ethylene glycol) (PEG), carrageenan and silver acetate. The concentration of solution was 9 wt%. The ratio of PVP : PEG : carrageenan was 6 : 1 : 2. The concentration of the silver acetate were 0, 0.01, 0.03, 0.05 and 0.07% and Gamma irradiation dose was 25 kGy. The Gamma irradiation dose in hydrogels with 0.01% silver acetate were 20 kGy, 35 kGy, 50 kGy, 65 kGy, and 80 kGy. The results showed that 0.01% silver acetate concentration of hydrogels by 25 kGy irradiation dose showed the highest antibacterial activity against E. coli and Staphylococcus aureus. Moreover, antibacterial activity of various Gamma irradiation dose in hydrogels treated 0.01% silver acetate showed highest 35 kGy irradiation dose against Staphylococcus aureus.

• Food Science and Preservation
• /
• v.30 no.5
• /
• pp.729-742
• /
• 2023

The consumption of king oyster mushrooms has steadily increased owing to their unique flavor and delicate texture. This study extended the storage period of king oyster mushrooms (Pleurotus eryngii ) via gamma irradiation. Irradiated samples (0, 0.5, 1, 2, and 3 kGy) were stored at 4℃ with 80% relative humidity for up to 28 days, and the experiments were conducted every 7 day. Microbiological analysis revealed a dose-dependent reduction in total aerobic bacteria, Pseudomonas spp., and yeasts and molds, and gamma irradiation above 2 kGy effectively controlled microbial contamination for up to 28 days. At the 28th day of storage, the irradiated king oyster mushrooms exhibited delayed browning through the reduction of tyrosinase activity. Moreover, firmness reduction (%) was 80.59±1.89% for the non-irradiated group and 42.80±1.28, 34.57±1.13, 31.05±3.24, and 39.73±0.94% for the irradiated group (0.5, 1, 2, and 3 kGy), respectively. These results were supported by the scanning electron microscopy photos, which showed smaller pores in the irradiated group than in the non-irradiated group. This study demonstrated that 2 kGy of gamma irradiation effectively reduces microbial contamination and delays the browning and softening of king oyster mushrooms for up to 28 days.

• Journal of Radiation Industry
• /
• v.17 no.1
• /
• pp.75-82
• /
• 2023

This research was carried out to evaluate on microbiological (total aerobic bacteria, yeast and mold) and physicochemical (color, firmness, water content, water activity and weight loss) characteristics of 10MeV electron-beam irradiated(0, 0.5, 1, 2 and 3kGy) enoki mushroom during storage (0, 7, 14, 21 and 28 day) at 4℃ with 80% relative humidity. As compared to control, all irradiated samples exhibited dose-dependent decreases of microbial counts up to 28 days, and electron beam irradiation above 2 kGy kept below the microbiological safety threshold. Yellowness (b^*) which is associated with discoloration of mushrooms was significantly reduced by electron beam irradiation (2 kGy). Firmness, water content, water activity and weight loss showed no significant difference in all group up to 28 days. Thus, the appropriate electron-beam irradiation dose was confirmed as 2 kGy to inhibit the microbial growth and browning reaction in enoki mushroom.

• Journal of Radiation Industry
• /
• v.7 no.2_3
• /
• pp.183-190
• /
• 2013

Mistletoe (Viscum album) has been widely used as a functional food material for various therapeutic purposes from ancient time. In this study, we examined anti-diabetic and cytotoxic activities of heated-treated mistletoe and the effects of gamma-irradiation on its activities. Heat-treated mistletoe extract was prepared by heating during different time (3, 6, 9 and 12 h) and gamma-irradiated with different doses of 0, 10, 30, 50, 70 and 100 kGy. Heat-treated mistletoe extracts showed a concentration-dependent cytotoxicity on rat insulinoma RINm5F cells and the effect was gradually decreased as heating time increased up to 12 h. 12 h heat-treated extract was no cytotoxic. Gamma-irradiation enhanced the reduction of heat-treated mistletoe-induced cytotoxicity and the decreasing effect was an irradiating dose-dependent. In particular, all of 70 kGy irradiated and heat-treated mistletoe extracts did not showed the cytotoxicity and the effect was comparable to 12 h heat-treated mistletoe extract. Among those extracts, 3 h heat-treated mistletoe extract gradually increased the insulin secreting activity by gamma-irradiation and the effect was the best at 70 kGy, whereas 12 heat-treated extract was no effect. On the test of ${\alpha}$-glucosidase inhibitory activity, 3 h heat-treated mistletoe extract showed the concentration dependent effects and gamma-irradiation induced more activity at 70 kGy, compared to non-irradiated 3 h and 12 h heated mistletoe extracts. These results suggest that the combination of heat treatment and gamma-irradiation might be more effective than only heat-treatment for improving the anti-diabetic activity of mistletoe extract and reducing its cytotoxicity.

• Journal of Radiation Industry
• /
• v.6 no.3
• /
• pp.217-221
• /
• 2012

The purpose of this study is to reduce the immune toxicity of lipopolysaccharide (LPS) by gamma irradiation. LPS was gamma-irradiated at the various doses of 20, 100 and 200 kGy and then evaluated on the immune toxicity through the cell proliferation, nitricoxide production and cytokine release. Cell proliferation significantly decreased in the intact LPS treated groups, whereas gamma-irradiated LPS treated group were not reduced the cell proliferation. Similarly, the production of nitric oxide and cytokine showed the high levels in the intact LPS treated group. However, gamma-irradiated LPS treated group remarkably decreased the production of nitric oxide and cytokine in dose-dependent manner. Therefore, gamma irradiation may effective method to reduce the immune toxicity of LPS.

• Journal of Radiation Industry
• /
• v.4 no.1
• /
• pp.25-31
• /
• 2010

Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lots of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment.

• Journal of Radiation Industry
• /
• v.10 no.4
• /
• pp.243-248
• /
• 2016

Argonaute 2 (AtAGO2) is a well characterized effector protein in Arabidopsis for its functionalities associated with DNA double-strand break (DSB)-induced small RNAs (diRNAs) and for its inducible expression upon ${\gamma}$-irradiation. However, its transcriptional regulation depending on the recovery time after the irradiation and on the specific response to DSBs has been poorly understood. We analyzed the 1,313 bp promoter sequence of the AtAGO2 gene ($1.3kb_{pro}$) to characterize the transcriptional regulation of AtAGO2 at various recovery times after ${\gamma}$-irradiation. A stable transformant harboring $1.3kb_{pro}$ fused with GUS gene showed that the AtAGO2 is highly expressed in response to ${\gamma}$-irradiation, after which the expression of the gene is gradually decreased until 5 days of DNA damage recovery. We also confirm that the AtAGO2 expression patterns are similar to that of ${\gamma}$-irradiation after the treatments of radiomimetic genotoxins (bleomycin and zeocin). However, methyl methanesulfonate and mitomycin C, which are associated with the inhibition of DNA replication, do not induce the expression of the AtAGO2, suggesting that the expression of the AtAGO2 is closely related with DNA DSBs rather than DNA replication.

• Journal of Radiation Industry
• /
• v.7 no.1
• /
• pp.55-59
• /
• 2013

Ionizing radiation causes the massive generation of reactive oxygen species, resulting in cellular and tissue damage. The present study was performed to evaluate ${\gamma}$-irradiation induced cellular damage in ICR mice. The mice were divided into four groups with ten mice in each group. Group 1 served as an unexposed control group. Groups 2, 3, and 4 were exposed to 3, 5, and 7 Gy of ${\gamma}$-radiation, respectively. Five mice per group were sacrificed 1 and 7 days after ${\gamma}$-radiation. Exposure to ${\gamma}$-irradiation resulted in hematopoietic damage in a dose-dependent manner when compared with the unexposed control group, which featured a significantly decreased spleen index. However, the exposed mice showed no significant differences in their serum AST, ALT and in the histopathological change of their liver. These results suggest that ${\gamma}$-irradiation is a good tool to prepare a hematopoietic damage model. This animal model can be employed to study the hematopoietic efficacy of biologically active compounds.