• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.729-733
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• 2005

This study was conducted to sanitize fried-frozen cheese ball by gamma irradiation. Total aerobic bacteria and yeasts and molds counts were 4.4 and 2.8 log CFU/g in non-irradiated sample, respectively. Microorganisms were decreased with increase of irradiation dose $(D_{10}=1.25\;kGy)$, and were not detected in samples irradiated at 3 kGy or more $(<10^2\;CFU/g)$. $D_{10}$ value for Escherichia coli (KCTC 1682) was 0.25 kGy. TBA (2-thiobarbituric acid) values were increased as irradiation dose was increased, but there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less (p<0.05). The results of sensory evaluation showed that there was no significant difference between non-irradiated and irradiated samples at 3 kGy or less, the sensory scores were decreased with irradiation at 5 kGy or more (p<0.05). These results indicated that gamma irradiation at 3 kGy was considered to be an effective treatment to ensure the microbiological safety of fried-frozen cheese balls without any sensorial change, even though further studies should be investigated to reduce detrimental effects induced by irradiation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.357-361
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• 2008

In this study, the antioxidant properties and physical characteristics of irradiated Sargassum siliquastrum water extract were evaluated. Samples were irradiated with $Co^{60}{\gamma}$-ray at doses ranging from 3 to 20 kGy. They were then analyzed to investigate antioxidant properties, including total phenolic compound content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity. In addition, physical properties such as viscosity and color were evaluated. The results demonstrated that total phenolic compound content and DPPH radical scavenging activity were significantly improved (p<0.05) by irradiation. In terms of physical properties, viscosity and color were reduced in the irradiated extracts as compared to non-irradiated samples. In conclusion, gamma irradiation improved the antioxidant properties of Sargassum siliquastrum water extract, improving its original weak point as a natural antioxidant when applied in the food industry.

• Korean Journal of Breeding Science
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• v.49 no.3
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• pp.150-156
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• 2017

This study was carried out to compare the survival and mutation rates and mutation spectrum by gamma-irradiation on rooted and unrooted cuttings of three spray type ('Lovelydia', 'Yellowbabe', and 'Haetsal') and two standard type ('Vital' and 'Aqua') cultivars in roses. Two groups, rooted and unrooted cuttings were gamma-irradiated at 70Gy for 24 hours. The irradiated rooted and unrooted cuttings were planted in a greenhouse, and survival, mutation rates and mutation spectrum were investigated 30 weeks after planting, respectively. As a result, survival and mutation rates of gamma-ray irradiated plants were 16.4%~50.8% and 0~5.1% for unrooted cuttings, and 39.4%~55.1% and 0.7%~7.4% for rooted cuttings, respectively. In conclusion, both survival and mutation rates were a little higher on rooted cuttings than on unrooted cuttings. However, when only survived plants after gamma-ray irradiation were considered, mutation rates were 0~10% and 1.8%~14.1% for unrooted cuttings and rooted cuttings, respectively, showing no significant difference. In addition, diverse variations on color and number of petals or shape of flowers were detected both in plants from rooted and unrooted cuttings, which indicated that there was no significant difference in mutation spectrum between two groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.427-432
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• 2004

Effect of gamma irradiation on porridge viscosity was studied. Vegetable, beef and pine nut dry flour porridges were irradiated at 0, 2.5, 5, 7.5 and 10 kGy, and rheological characteristics and sensory qualities of irradiated porridge were evaluated. Hunter color lightness were decreased, while redness were increased in dry flour porridge with the increase of irradiation dose. Firmness, consistency, cohesiveness and viscosity of dry flour porridge were significantly decreased with the increase of irradiation dose (p<0.05). Vegetable, beef and pine nut dry flour porridges at dose of 10 kGy reduced the viscosity with 93%, 71% and 55%, respectively Irradiation greatly reduced the viscosity of porridges, probably by starch depolymerization. Irradiation increased the total solids and thus, can improve the calorie up to 30 ㎉. Gamma irradiation was effective in enhancing calorie value of porridge due to reduction of viscosity. As a result of sensory evaluation, overall acceptability and the quality characteristics of irradiated porridges (up to S kGy) were not significantly different from those of the control (p<0.05). In the vegetable porridge, the irradiated porridge at dose of 2.5 kGy was a significantly better overall acceptability than the non-irradiated porridge (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.57-63
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• 2002

As an alternative to methyl bromide (MeBr) fumigation for the control of quarantine pests of pears (Pyrus pyrifolia cv. Niitaka), the effect of gamma irradiation (0.5~3 kGy) was comparatively investigated. Insects found in the pears were identified Tetranychus urticae Koch and Panonychus ulmi Koch, which were of quarantine importance. These insects were easily destroyed by MeBr even one day after fumigation. Whereas irradiation at 0.5~2 kGy was not enough to reach the mortality, even if 3 kGy showed the same mortality as MeBr after 17 days of treatment. Respiration of pears was stimulated by both increased doses of irradiation and MeBr fumigation. The rates of surface blackening and core browning were accelerated by MeBr rather than higher doses of irradiation. While the changes in flesh firmness and surface color were more apparent in irradiated samples at above 2 kGy than MeBr. There were negligible differences in the contents of titratable acidity, acetaldehyde and ethanol by the treatment conditions except for 3 kGy-irradiated group. Sensory evaluation showed that mere than 1 kGy was the threshold to induce the significant changes in quality of pears.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1843-1847
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• 2013

This study is carried out to sanitize rape (Brassica napus) pollen by gamma irradiation. Rape pollens were treated with 0, 5, 10 and 15 kGy gamma irradiations, and then analyzed for the following: general composition, microbial population, reducing sugar, Hunter color values, TBARS (2-thiobarbituric acid reactive substances) values, and VBN (volatile basic nitrogen). Mold and coliform bacteria were not detected in the samples irradiated at 5 kGy or more. Yeasts and total aerobic bacteria were not detected in the samples irradiated at 10 kGy or more (<$10^2$ CFU/g). Moisture, ash, crude protein, crude fat, carbohydrate, reducing sugar and the contents of volatile basic nitrogen in the irradiated pollen did not show any significant changes by irradiation. Hunter color values, $L^*$, $a^*$ and $b^*$ values were decreased with increment of irradiation dose. TBARS values were increased with an increment of irradiation dose. In conclusion, gamma irradiation at 5 kGy was considered to be an effective treatment to control for mycotoxin producing fungi in rape pollen to minimize changes of general composition and physicochemical properties. Further studies should be investigated to reduce the detrimental effects induced by irradiation.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.125-132
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• 2006

The PET/CT scanner is an evolution in image technology. The two modalities are complementary with CT and PET images. The PET scan images are well known as low resolution anatomic landmak, but such problems may help with interpretation detailed anatomic framework such as that provided by CT scan. PET/CT offers some advantages-improved lesion localization and identification, more accurate tumor staging. etc. Conventional PET employs tranmission scan require around 4 min./bed position and 30 min. for whole body scan. But PET/CT scanner can reduced by 50% in whole body scan. Especially nowadays PET scanner LSO scintillator-based from BGO without septa and operate in 3-D acquisition mode with multidetectors CT. PET/CT scanner fusion problems solved through hardware rather than software. Such device provides with the capability to acquire accurately aligned anatomic and functional images from single scan. It is very important to effective detection from gamma ray source in PETdetector. And can be offer high quality diagnostic images. So we have study about detection processing of PET detector and high quality imaging process.

• Research in Plant Disease
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• v.20 no.4
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• pp.283-288
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• 2014

Citrus canker caused by Xanthomonas citri subsp. citri (Xcc) has been quarantined by many countries in the world. Recently, the usage of methyl bromide should be limited, application by gamma irradiation on the agricultural production is raised as an alternative method. In this study, the level of gamma irradiation which could decrease of population of Xcc in the suspension or on the surface of citrus fruit was investigated. The $D_{10}$ value of Xcc, which is radiation dose required to reduce the number of the microorganism, was 55 and 28 Gy in the suspension and on the surface of citrus fruit, respectively. Furthermore, disease severity was suppressed on the citrus leaves inoculated with Xcc suspension pre-treated with gamma irradiation. Based on this study, it is suggested that Xcc on the citrus fruit could be eradicated by gamma irradiation and the results of this study may be valuable for application of gamma ray in quarantine activity.

• Food Science and Preservation
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• v.16 no.2
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• pp.286-291
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• 2009

Microorganisms in seafood cooking drips were counted and identified. Total viable cell counts were 6.40 and 3.10 log CFU/g in cooking drips of Hizikia fusiformis and Thunnus thynnus, respectively. However, microbial populations fell with increased irradiation doses. In H. fusiformis cooking drips, a 5-log reduction in total aerobic bacteria was obtained by irradiation with 5 kGy. In T. thynnus cooking drips, however, contaminating microorganisms were more resistant to gamma irradiation and only a 1-log reduction was seen. DNA sequence analysis showed that the principal contaminating microorganisms in H. fusiformis and T. thynnus cooking drips were Lactobacillus and Bacillus species, respectively. Therefore, the high irradiation resistance of T. thynnus cooking drips microbes may result from spore formation by Bacillus species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.687-693
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• 2004

The objective of this study was to evaluate the combined treatment effect of gamma irradiation and rosemary extract powder on ready-to-eat hamburger steaks. After irradiation at 5, 10 and 20 k㏉, hamburger steaks manufactured with rosemary extract powder (200 and 500 ppm) were stored at 5$^{\circ}C$ for 4 months and at 3$0^{\circ}C$ for 3 weeks. Total aerobic bacteria count of the ready-to-eat hamburger steak was approximately 5 log CFU/g level. All doses of gamma irradiation were effective in reducing the population of total aerobic bacteria and coliform bacteria in hamburger steaks. In hamburger steaks irradiated at 20 k㏉, tile microbial growth was not observed during storage. The shelf-life of hamburger steaks were determined by microbiological counts of 10$^{6}$ ∼10$^{7}$ CFU/g and those of the steaks irradiated at 0, 5 and 10 k㏉ were ranged among 14, 28∼42 and 98∼112 days, respectively. The shelf-life of both irradiated hamburger steaks added with 500 ppm rosemary extract powder at 5 and 10 k㏉ was extended more 14 days than non-added sample. Results suggested that both gamma irradiation and rosemary extract powder may improve the shelf-stability of ready-to-eat ham-burger steak. However, when the storage temperature was abused (3$0^{\circ}C$), the rosemary extract powder had not sufficient effect on the shelf- stability of hamburger steaks.