• Journal of Radiation Industry
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• v.6 no.2
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• pp.153-158
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• 2012

In this research, poly(acrylic acid) (PAAc) hydrogels containing zinc oxide particle were prepared by gamma-ray irradiation. PAAc powder was completely dissolved in distilled water at room temperature. Water-insoluble zinc oxide powder were added into the PAAc solution and stirred until totally dissolved. Finally, the mixture was irradiated by gamma-ray irradiation to make crosslinking. The effects of various parameters such as zinc ions' concentration, irradiation doses were varied and investigated in detail. PAAc hydrogels containing zinc oxide particle were characterized by gel content and swelling ratio. Moreover, the antibacterial properties of this material were evaluated by paper diffusion test against the Gram positive and Gram negative bacteria.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.59-64
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• 2010

This study was conducted to evaluate the microbial (Total aerobic count, Coliform, Coagulase positive Staphylococci, Salmonella, Yeast/Mold, Escherichia coli, Bacillus cereus), Hunter'color values ($L^*$, $a^*$, $b^*$) and organoleptic quality of freeze-dried Miyeokguk, Korean seaweed soup in space food. Bacillus cereus was 1 log level while not detected in the sample irradiated at 10 kGy. Hunter's color values of the samples irradiated less than 10 kGy was not significantly different (p>0.05). The sensory evaluation result showed that the preference scores in all the sensory properties decreased when it was irradiated over 10 kGy, but sensory score of less than 10 kGy samples was similar in all terms. Therefore, it was considered that gamma irradiation at 10 kGy was enough to sterilize the freeze-dried Miyeokguk without deterioration of sensory quality.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.1-7
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• 2008

Active polymer gels expand and contract in response to certain environmental stimuli, such as the application of an electric field or a change in the pH level of the surroundings. This ability to achieve large, reversible deformations with no external mechanical loading has generated much interest in the use of these gels as biomimetic actuators and artificial muscles. In this study, poly (vinyl alcohol)(PVA) grafted acrylic acid monomer (PVA-g-AAc) hydrogels were prepared by $^{60}Co$ ${\gamma}-ray$ irradiation and their properties such as degree of grafting and weight swelling in electrostimulation as an artificial muscle and actuator were investigated.

• Journal of Radiation Industry
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• v.2 no.1
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• pp.43-51
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• 2008

Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.267-272
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• 2011

This study evaluated the microbial population (total aerobic count, fungi) and organoleptic quality of freeze-dried bibimbap sterilized by gamma irradiation to develop the space food. An irradiation dose above 30 kGy was needed to sterilize the freeze-dried bibimbap, while organoleptic quality of the sample was significantly decreased by irradiation (p<0.05). However, it was observed that scores on overall acceptance of rehydrated bibimbap after irradiation were the highest, when vitamin C and paprika extract were added at 0.1%, respectively. Therefore, it was considered that the freeze-dried bibimbap could be developed as a space food, which meet microbial requirements and organoleptic quality through addition of vitamin C 0.1% and paprika extract 0.1% before gamma irradiation at 30 kGy.

• Journal of Radiation Industry
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• v.3 no.1
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• pp.13-18
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• 2009

In earlier investigations, seeds of Perilla frutescens(L.) Britt. cv. Chookyoupjaso were irradiated with 200 Gy gamma ray to generate mutagenesis. The aim of this study is to investigate the effects of a hexane extract from Perilla frutescens (L.) Britt. cv. Chookyoupjaso mutant 45 on the actions of anti-inflammatory activity on inducible nitric oxide synthase, and an identification of the major active compound. The hexane extract from P. frutescens exhibited activity of inhibition of a NO production ($IC_{50}$, $295.1{\mu}g\;ml^{-1}$). The hexane extract was further divided into subfractions by silica-gel chromatogarphy. Inhibition of the NO production by various fractions was assayed in LPS-stimulated RAW 264.7 cells. Among the seven fractions, the 5th fraction was the most effective ($IC_{50}$, $19.5{\mu}g\;ml^{-1}$). The 5th fraction suppressed the expression of protein of iNOS in LPS-induced RAW 264.7 cells, and GC/MS analyses showed that isoegomaketone is a major bio-active compound in the 5th fraction. The result indicated that isoegomaketone has a good potential to be developed as an anti-inflammation agent.

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

• 대한핵의학회:학술대회논문집
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• 1978.06a
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• pp.65.1-65.1
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• 1978

• Journal of Radiation Industry
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• v.5 no.1
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• pp.47-54
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• 2011

In this study, we investigated to evaluate differential expression of genes encoding lipid transfer proteins (LTP) by acute and chronic gamma irradiation in rice. After acute and chronic gamma irradiation by 100 Gy and 400 Gy to rice plant, necrotic lesion was observed in the leaf blade and anthocyanin contents were increased. We isolated a total of 21 rice lipid transfer protein (LTP) genes in the TIGR database, and these genes were divided into four different groups on the basis of nucleotide sequences. The LTP genes also were classified as different four classes according to expression pattern using RT-PCR. Group A, B contained genes with increased expression and decreased expression in acute and chronic, respectively. Group C contained genes with contrasted expression pattern. Group D wasn't a regular pattern. But the specific affinity was not obtained between two grouping.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.175-178
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• 2011

This study was conducted with effect of lactic acid bacteria by gamma irradiation. Lactic acid bacteria were exposed to irradiation with a single absorbed dose of 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Possible lactic acid bacteria, including Lactobacillus paracasei KCTC 13169, Lactobacillus casei KCTC 3109, Lactobacillus acidophilus KCTC 3140, Lactobacillus plantarum subsp plantarum KCTC 3103, Lactobacillus debruekii subsp bulgaricus KCTC 3635, Streptococcus thermophilus KCTC 3658 were selected. The radiation sesitivities of lactic acid bacteria were expressed as $D_{10}$ values. The $D_{10}$ values of Lactobacillus paracasei, Lactobacillus casei, Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus debruekii were calculated as 0.42, 0.51, 0.47, 0.90, 0.44, and 0.61 kGy, respectively. Results suggest that L. acidiphilus has the highly resistant to gamma irradiation.