• Food Science and Preservation
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• v.15 no.5
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• pp.648-655
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• 2008

A gamma irradiation process was applied to prolong the shelf-life of grapes and changes in microbiological, physicochemical, nutritional, and sensory characteristics were investigated during 6 weeks of post-irradiation storage at $4^{\circ}C$ and $25^{\circ}C$. Physiochemical characteristics of grapes such as total sugar content, pH, titratable acidity, and anthocyanine content, were stable after 1 kGy of irradiation, a dose recommended by CODEX for fruits and vegetables. The viable cell counts of contaminating microorganisms were reduced 1-2 logs by this radiation dose. After 6 weeks of storage at $4^{\circ}C$ the microbiological quality of irradiated grapes was stable, but all non-irradiated grapes had deteriorated. Whether or not grapes were irradiated, weight loss rapidly increased after 2 weeks of storage at $25^{\circ}C$, whereas weight loss was delayed by storage at $4^{\circ}C$. Immediately after gamma irradiation, the sensory evaluation results did not differ between samples, and the sensory quality of the irradiated grapes remained acceptable for over 6 weeks of storage at $4^{\circ}C$. The results suggest that 1 kGy of gamma irradiation does not detrimentally affect the nutritional or physical characteristics of grapes, especially when cold storage follows radiation treatment. In conclusion, a combination of gamma irradiation and cold storage prolonged the shelf-life of grapes by 6 weeks.

• Journal of Food Hygiene and Safety
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• v.11 no.3
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• pp.221-225
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• 1996

For the purpose of improving hygienic quality of health-foods, sterilization effects of ${\gamma}$-ray and ozone on microoganisms associated with food cultured in the media and contaminated in Angelica keiskei powder were investigated. Ozone was immersed in water and sprayed in air, on the concentration of 3 mg liter-1 at an air flow rate of 5 liter min-3. Test strains cultured in the media completely inhibited by ${\gamma}$-ray at irradiation doses of 0.25~2 kGy. In the case of ozone, test bacteria inactivated after treatment of 10~20 minutes, but test mold, Aspergillus flavus was not effective. Strains contaminated in Angelica keiskei powder completely inhibited by ${\gamma}$-ray at irradiation doses of 2.5~7.5 kGy. However, when the powder was sprayed with ozonized air for 10hours, Bacillus subtilis and Staphylococcus aureus among five strains were eliminated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.437-440
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• 2004

The radiation-induced changes taking place in poly(vinylidene fluoride)(PVDF) exposed to $^{60}Co\;\gamma-ray$ irradiation were investigated in correlation with the applied doses. Samples were irradiated in air at room temperature by $^{60}Co\;\gamma-ray$ to doses in the range of 200 to 1000 kGy. Various properties of the irradiated PVDF were studied using nm, differential scanning calorimetry(DSC) and gel fraction. $^{60}Co\;\gamma-ray$ irradiation was found to induce changes in chemical, thermal, structural properties of PVDF and such changes vary depending on the radiation dose.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.67-71
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• 1999

Effect of single intraperitoneal administration of Cordyceps sinensis (Cs) extract at 24 hour before whole-body ${\gamma}$ - irradiation on the survival ratio, body weight, organ weight changes and serum metabolites in the irradiated mice were investigated. The single pre-administration of Cs extract increased the 40-day survival ratio of irradiated mice from 66.7% to 83.4%. The administration of Cs extract completely prevented weight reductions of spleen and thymus produced by ${\gamma}$ - irradiation (P<0.05, P<0.01). Similar but somewhat less radioprotective effect was also found in the testis of the Cs treated mice. The administration of Cs inhibited the serum hyperglycemia produced by irradiation on the day 7th(P<0.01). However, it did not influence the serum cholesterol and protein levels on the days examined. The present study is the first report regarding Cs which was tested and found to be radioprotective.

• Journal of Radiation Industry
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• v.5 no.1
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• pp.35-39
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• 2011

This study was investigated the effect of tumor cell cytotoxicity of gamma irradiated Chaga mushroom extract (CME). CME was prepared by hot water extraction at $70^{\circ}C$ for 4 hours and lyophilized. $Ten\;mg\;ml^{-1}$ of lyophilized CME powder was dissolved with deionized water and then irradiated at the doses of 10, 50, 100, and 150kGy by cobalt 60 gamma irradiator. The gamma-irradiated and non-irradiated CME were treated into the cancer cell, including human stomach cancer and human colon cancer. Cytotoxicity against the cancer cell was increased in gamma-irradiated CME and antioxidant activity was also increased in gamma-irradiated CME, as irradiation dose increased. Therefore, it was considered that gamma irradiation was effective method for improvement of the cancer cell cytotoxicity and antioxidant activity of Chaga mushroom extract.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1129-1134
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• 2003

Changran jeotkal, a Korean traditional fermented seafood, was prepared as a pilot scale using a commercial method and irradiated at 0, 2.5, 5.0 and 10 kGy by gamma ray to investigate possibilities for further industrial application. To see the effectiveness and rapid industrialization, hot pepper powder was irradiated at 10 kGy and manufactured the changran jeotkal (HP-10 kGy) as same method since the hot pepper powder was approved legally for gamma irradiation in Korea. The content of volatile basic nitrogen and amino nitrogen was significantly reduced by gamma irradiation in all storage periods. Amino nitrogen contents of 0, 2.5, 5.0, 10 kGy and HP-10 kGy were 98.9, 98.5, 92.4, 88.0 and 93.1mg%, respectively after 12 week of storage at $10^{\circ}C$. In total, 8 kinds of biogenic amines were found from the samples, and the contents in the gamma irradiated changran Jeotkal were lower than those of the control during storage. The sample of HP-10 kGy showed similar physicochemical characteristics to the sample irradiated as $2.5{\sim}5.0\;kGy$. Results indicated that gamma irradiation of fermented seafood products such as seasoned changran jeotkal improved quality stability, thus, we recommend gamma irradiation for industrial application.

• The Korean Journal of Zoology
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• v.12 no.4
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• pp.114-122
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• 1969

Electron microscopic examination of the liver and heart tissues of methylene blue-treated rats before gamma-irradiation was observed in this study. 1. It was observed severe alteration and degeneration of organelles: accumulation of glycogen particles, severe swollen mitochondria, and broken endoplasmic reticulum in liver tissue of saline-treated rat(control) opposed by emthylene blue-treated rat at 64 and 212 hours following gamma-irradiation. 2. Heart muscles of both methylene blue-treated and saline-treated rats showed no significant alterations, but it was observed that slightly elongated mitochondria with broken cristae and some of vacuoles as well as increased glycogen particles in sarcoplasmic reticulum at 212 hours following gamma-irradiation. 3. It may be considered that methylene blue greatly reduces the sensitivities of rats to gamma-irradiation.

• 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).

• Korean Journal of Veterinary Research
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• v.43 no.4
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• pp.633-639
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• 2003

We investigated the effect of green tea and its fractions of alcohol and polysaccharide on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gamma-irradiation. Jejunal crypts were protected by pretreatment of green tea (i.p.: 50 mg/kg of body weight, at 12 and 36 hours before irradiation., p.o.: 1.25% water extract, for 7days before irradiation, p<0.01) and alcohol and polysaccharide fractions showed no significant modifying effects. Green tea and its fractions administration before irradiation (i.p. at 12 and 36hours before irradiation) resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (i.p. at 12 and 36 hours before irradiation, p<0.05., p.o. for 7days before irradiation, p<0.001) and its fractions (p<0.001). These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.84-89
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• 1972

An experiment was carried out to investigate the optimum doses of gamma-irradiation for sprouting inhibition of onion bulbs with irradiation time and storage conditions. The results. obtained are as follows: 1) The irradiation doses of 5, 7 and 10 krad, respectively, at 11, 32 and 66 days after harvest were sufficient to inhibit subsequent sprout of onion bulbs obtained from Nampyeong district. When they were irradiated at 96 day after harvest, however, there was little sprout-inhibition by 15 krad. In case of onion bulbs obtained from Changnyeong district, sprout was inhibited by doses of 8 and 12 krad respectively, at 51 and 89 days after harvest. 2) Low-temperature storage after irradiation was not effective in sprout-inhibition of onion bulbs. Onion bulbs stored at low temperature of $5^{\circ}C$ rather showed higher sprouting rate as compared with that of room temperature. 3) Rot increased in irradiated lot and at room temperature, and spores of Aspergillus sp. were little germinated at a level of 100 krad. 4) The respiratory rate of irradiated onion bulbs was higher immediately after irradiation but lower one week after irradiation than control. Respiratory quotient of tissues seems to be little affected by gamma-irradiation.