• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.107-112
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• 1997

The effect of gamma-irradiation sterilization on molecular structural changes in orthopaedic surgical-grade polyethylene was studied. The relative crystallinity ud. percent crosslinking of the substance increased as a result of the gamma irradiation and varied anisotropically as a function of depth. Samples from the articulating surfaces showed 5% Venter relative crystallinity than those from the mid-sections, whereas samples from the mid-sections exhibited 15% greater crosslinking than those from the surfaces. These anisotropic variations are discussed in assDciation with oxidation.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.808-815
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• 2022

In this study, gamma-irradiated mackerel (Scomber japonicus) meat was stored in a refrigerator for 20 days to examine the physicochemical changes related to fishy smell. The effect of gamma irradiation on the inhibition of the activity of crude urease extracted from Vibrio parahaemolyticus was also evaluated. Increased levels of trimethylamine (TMA) and volatile basic nitrogen (VBN) content, which are the main components causing fishy smell, were significantly reduced by day 20 of storage after gamma irradiation, indicating that freshness was maintained during storage. The ammonia nitrogen contents of 3, 7, 10, and 20 kGy gamma-irradiated groups were significantly decreased by 6.5, 15.2, 17.4, and 23.9%, respectively, compared to non-irradiated groups on day 20 of storage. In addition, urease activity decreased in a gamma irradiation intensity-dependent manner. Volatile organic compounds (VOCs) were measured during the storage of gamma-irradiated mackerel meat. The contents of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavors due to spoilage of fish, were significantly reduced by day 20 of storage. Therefore, gamma irradiation can be considered useful for inhibiting urease activity and reducing fishy smell during fish storage.

• Parasites, Hosts and Diseases
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• v.49 no.1
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• pp.25-31
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• 2011

Cryptosporidium parvum is known as one of the most highly resistant parasites to gamma irradiation. To morphologically have an insight on the radioresistance of this parasite, ultrastructural changes in C. parvum sporozoites were observed after gamma irradiation using various doses (1, 5, 10, and 25 kGy) following a range of post-irradiation incubation times (10 kGy for 6, 12, 24, 48, 72, and 96 hr). The ultrastructures of C. parvum oocysts changed remarkably after a 10-kGy irradiation. Nuclear membrane changes and degranulation of dense granules were observed with high doses over 10 kGy, and morphological changes in micronemes and rhoptries were observed with very high doses over 25 kGy. Oocyst walls were not affected by irradiation, whereas the internal structures of sporozoites degenerated completely 96 hr post-irradiation using a dose of 10 kGy. From this study, morphological evidence of radioresistance of C. parvum has been supplemented.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.191-195
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• 2003

We investigated the effects of gamma irradiation on the microbiological, chemical and sensory qualities of bulgogi, a traditional Korean meat product. Gamma irradiation reduced the number of coliform bacteria and bacterial colonies counted in Salmonella-Shigella selective agar to a non-detectable level. Thermophillic microorganisms (mainly Bacillus spp.) in bolgogi refrigerated for 20 days were also significantly reduced by 3 log cycles by 2.5 to 7.5 kGy of irradiation, compared to the control. Electron donating ability and shear force of ready-to-cook bulgogi was not significantly affected by gamma irradiation. Irradiation increased the 2-thiobarbituric acid reactive substances (TBARS) value. The irradiated, raw, ready-to-cook bulgogi had significantly higher scores in color and appearance than those of non-irradiated controls from sensory evaluation. The overall acceptance of cooked bulgogi had higher scores in non-irradiated or 2.5 kGy-irradiated bulgogi than the 5.0- or 7.5-kGy irradiated counterparts. In conclusion, irradiation at 2.5 kGy is recommended as a method to improve shelf-life, safety, and to achieve acceptable quality of ready-to-cook bulgogi without any adverse changes in the sensory characteristics.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.89-95
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• 1997

The comparative effects of gamma irradiation an ozone treatment on the microbiological and physicochemical qualities were investigated for the improvement of hygienic quality of aloe powder and bee pollen. Gamma irradiation at 7.5~10kGy could reduce total aerobic bacteria, molds and coliforms below detection levels, but ozone treatment up to 18 ppm for 8hr was not sufficient to eliminate the microorganisms from aloe powder and bee pollen. The physicochemical properties such as fatty acid an amino acid compositions, mineral content, TBA value, barbaloin and pigment contents were not significantly changed by gamma irradiation, whereas ozone treatment caused significant changes in fatty acid composition, lipid oxidation and destruction of barbaloin and natural pigments.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.41-47
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• 1999

To investigate the combined effect of gamma ray irradiation and NaCl treatment on Tradescantia somatic cell pink mutations, potted plants of Tradescantia 4430 were evenly sprayed with NaCl solution(170mM) 24 hours before irradiation(NaCl+${\gamma}$) and after irradiation(${\gamma}$+NaCl). Irradiation doses were 0.3, 0.5, 1.0 and 2.0 Gy of gamma-ray. The plants irradiated only with gamma radiation were used as control group(CT). Frequency of pink mutation increased linearly with irradiation close and the peak interval of elevated mutation frequencies appeared during 6∼12 days aver irradiation in all the experimental groups. The slope of dose-response curve in CT was 5.99($r^2$=0.99), while it were 4.55($r^2$=0.98) in NaCl+${\gamma}$ and 4.33($r^2$=0.99) in ${\gamma}$+NaCl. It seemed that pre- and post-treatment of NaCl had a protective effect it against radiation-induced cell damages since it decreased the slope value by more than 24%. It is suggested that protective effect on DNA damages can be invoked in irradiated stamen hair cells by NaCl treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.50-57
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• 2011

This study examined the effect of gamma irradiation (3-20 kGy) on the immune activity and physicochemical properties of Myagropsis myagroides (MM) water extracts. MM powder and water extracts were subjected to gamma irradiation at 3, 7, and 20 kGy. The effects of gamma-irradiated MM water extracts on splenocyte proliferation and cytokine IFN-${\gamma}$ and IL-2 secretion were evaluated. The gamma-irradiated MM water extracts resulted in decreased splenocyte proliferation without cytotoxicity. The IFN-${\gamma}$ and IL-2 secretion increased by gamma-irradiated MM water extracts with increasing irradiation dose. For MM powder, the yield and total phenolic compounds (TPC) of water extracts were increased slightly after gamma irradiation. In MM water extracts, the TPC was higher at a dose of 20 kGy, while gamma irradiation decreased the viscosity, pH, and color of the MM extracts. In conclusion, gamma irradiation improved the immunomodulatory activity of MM water extracts, overcoming its potential weakness when applied in the food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.500-504
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• 2001

Gamma irradiation was applied to reduce egg allergy. Ovalbumin (OVA), an egg white protein, was used as model allergen and was gamma-irradiated at 3, 5, or 10 kGy in an aqueous state (2.0 mg/mL). The changes in allergenic and antigenic properties of OVA resulted from gamma irradiation were monitored by ELISA with serum from egg-hypersensitive patients (H-IgE), and mouse monoclonal IgG (M-IgG) or rabbit polyclonal IgG (R-IgG). The binding ability of H-IgE to irradiated OVA was dose-dependently reduced. However, IgGs from animal did better recognize 3 or 5 kGy-irradiated OVA. In the evaluation of immune reactivity using blind test, the reactivity of H-IgE rapidly decreased depending upon the irradiation dose. However, the reactivities of M-IgG and R-IgG was higher at 5 and 3 kGy-irradiated OVA than non-irradiated control. The results provide a new possibility to use irradiation process for reducing the allergenicity of egg white.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.723-727
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• 2008

The effect of gamma irradiation on the prevention of breeding a patulin-producing mold and reducing patulin content was evaluated in an apple model system. Penicillium griseofulvum, a patulin-producing standard mold strain was artificially inoculated into apples and a gamma irradiation was performed. The $D_{10}$-values of the conidia of P. griseofulvum in an aqueous suspension and the apple model system were calculated at 0.28 and 0.48 kGy, respectively. The viable cell counts of the inoculated conidia in the apples showed 2 decimal point reductions at a dose of 1 kGy. Breeding and growth of the survived conidia was prevented during 10 weeks of post-irradiation storage period, especially at $4^{\circ}C$. The concentration of patulin in the non-irradiated apples was gradually increased and reached about 950 ppm at $25^{\circ}C$ and 410 ppm at $4^{\circ}C$, but the production of patulin was not observed during storage after 1 kGy of gamma irradiation.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.7-10
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• 2014

This study was designed to evaluate the protective effect of silkworm hemolymph against ${\gamma}-irradiation$ induced damage in the liver of mice. Female Balb/C mice (6 weeks old) were exposed to ${\gamma}-irradiation$ (6 Gy) and administered orally to silkworm hemolymph ($5ml\;kg^{-1}$ BW) for 7 days post-irradiation. The body weight, spleen index, plasma aspartate transaminase (AST), plasma alanine transaminase (ALT), and liver malondialdehyde (MDA) levels were determined. Compared with irradiated control mice, the activity of plasma AST and the level of MDA were significantly decreased in mice treated silkworm hemolymph. These results show that silkworm hemolymph is found to have a protective effect against ${\gamma}-irradiation$ induced damage in mice.