• 한국식품과학회지
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• 제17권4호
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• pp.311-318
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• 1985

This review was intended to develop the sterilization method of spices by gamma irradiation and the results are summarized as follows. Microbial load of spices was different according to the kind of spices and the number was ranged from $10^{2}$-$10^{5}/g$ to $10^{7}$-$10^{8}/g$, gamma irradiation up to 4-10 kGy could decreased or sterilized to the microorganism of spices. In physicochemical properties of spices such as chemical components,essential oil and flavor, irradiated group with optimum dose was almost similar to the nonirradiated one, while fumigant treated group was remarkably deteriorated in the properties of spices compared with control, and free radicals produced by irradiation was disappeared during a few days storage. Irradiated spices should be an aptitude for good quality the storeability of processing food. Optimum dose irradiation below less than that proposed by FAO/IAEA/WHO Joint Committee and FDA was remarkably effect on the sterilization of spices and superior in wholesomeness and economic feasibiity compared with traditional methods. Irradiation might be an alternative to traditional sterilization methods of spices by fumigants such as ethylene oxide and ethylene dibromide because their treatments have been banned in U.S.A and other countries since 1982.

• 한국축산식품학회지
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• 제18권3호
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• pp.232-239
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• 1998

This experiment was conducted to investigate radurization effects of gamma ray and electron beam irradiation at 1.5 and 3.0 kGy on beef steaks during 8 days of storage at 5$^{\circ}C$. Total bacteria count, psychrotrophs, mesophiles and thermophiles were analyzed at 2 days intervals. Nonirradiated beef steak was used a scontrol Total bacteria counts, psychrotrophs, mesophiles and thermophiles of the control samples showed 3.03∼4.72 logCFU / g at 0 day and increased to 7.67∼10.90 logCFU / g during 8 days storage except thermophiles. Total bacteria counts, psychrotrophs and mesophiles of beef steaks at 8 days were significantly (p＜0.05) decreased to 3.61∼5.43 logCFU / g by gamma ray and to 3.83∼7.02 logCFU / g by electron beam irradiation at 1.5 and 3.0 kGy. Thermophiles of all irradiated samples at any dose were not detectable through 8 days storage. These results suggested that both gamma ray and electron beam irradiation were effective to extend lag phase of bacterial growth of refrigerated beef. Gamma ray irradiation was better than electron beam irradiation in terms of radurization effects of beef.

• 한국식품위생안전성학회지
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• 제14권2호
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• pp.160-166
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• 1999

Microbial populations of total aerobic bacteria and coliforming bacteria, TBA, Hunter's color value, heme pigments, muscle protein solubility, cooking loss and shear force were investigated fro evaluating the shelf life of chicken legs gamma-irradiated at doses of 1, 3, 5 and 10 kGy with air-contained and vacuum-packaged methods. The initial microbial populations decreased with gamma irradiation depending upon the dose, and microorganisms in the vacuum-packaged samples were inhibited more than those in the air-contained samples. Hunter's L and a values of the surface and inside of the legs increased by gamma irradiation, showing a bright red color and the red color was maintained during the storage of both samples. The concentrations of oxymyoglobin among the heme pigments increased by gamma irradiation. Muscle protein solubility slightly increased by increasing the applied dose. There were no significant differences in the cooking loss and shear force values. In conclusion, the combination of gamma irradiation and vacuum-packaging could extend the shelf life of chilled chicken without deterioration of the quality.

• 대한안전경영과학회지
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• 제4권4호
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• pp.137-146
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• 2002

In order to investigate the effect of irradiation by $^{60}Co-\gamma$rays as well as the e thermal treatment on the dielectric deterioration in ethylene propylene rubber, insulating material for electric cables used in atomic power plants, charging discharging current, residual built- up voltage and dielectric properties are measu discussed in this study. Variance in the characteristic of relative dielectric constant as a function of tem was observed in relatively high dose of irradiation. Since glass transition tem appeared at tens of degree Celsius below zero, the characteristic is attributed orientation polarization. Dielectric loss is generally increased, with increasing d irradiation in the characteristic of dielectric loss as a function of temperature, No d loss by thermal treatment was observed. Dielectric resistance decreases with increa of irradiation in the characteristic of charging current as a function of temperature be considered that dielectric resistance seems to be recovered by thermal treatm characteristic of discharging current as a function of time in the specimen less ir become similar to that of the unirradiated, when thermal treated. A peak is shown residual built- up voltage as a function of time, and the corresponding time of the shorten as increasing dose of irradiation. It is also observed that the corresponding the peak is lengthened by thermal treatment.

• Food Science and Biotechnology
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• 제17권4호
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• pp.861-864
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• 2008

Enterobacter sakazakii, Salmonella typhimurium. and Bacillus cereus were evaluated on inoculated infant formula by gamma irradiation treatment as a method to provide microbial safety. The infant formula inoculated with the major pathogenic bacteria was treated at irradiation dose of 0, 3, 5, and 10 kGy, respectively. After treatment, the samples were individually packaged and stored at $20^{\circ}C$. Microbiological data during storage represented that the populations of E. sakazakii, S. typhimurium, and B. cereus were reduced with the increase of irradiation dose by 4 to 5 log reductions. In particular, E. sakazakii, S. typhimurium. and B. cereus were eliminated at 10, 5, and 3 kGy, respectively. E. sakazakii was the most radiation-resistant, while B. cereus was the least. Our results represent that gamma irradiation below 10 kGy should eliminate the growth of the major pathogenic bacteria in infant formula during storage.

• 대한금속재료학회지
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• 제50권8호
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• pp.583-589
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• 2012

This work is concerned with a statistical approach to the life prediction on irradiation-assisted stress corrosion cracking (IASCC) of stainless steel (SS) for core internals of a pressurized water reactor (PWR). The previous results of the time-to-failure of IASCC measured on neutron-irradiated stainless steel components were statistically analyzed in terms of stress and irradiation. The accelerating life testing model of IASCC of cold worked Type 316 SS was established based on an inverse power model with two stress-variables, the applied stress and irradiation dose. Considering the variation of the yield strength and applied stress with the irradiation dose in the model, the remaining life of the baffle former bolt was statistically predicted during operation under complex environments of stress and irradiation.

• Imaging Science in Dentistry
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• 제30권1호
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• pp.71-79
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• 2000

Purpose : This study was aimed to evaluate the cell cycle arrest and apoptosis induction after irradiation and epidermal growth factor (EGF) treatment in three human epithelial tumor cell lines (A431, Siha, KB). Materials and Methods: Single irradiation of 2, 5 and 10 Gy was done on three cell lines with 5.38 Gy/min dose rate using Cs-137 irradiator at room temperature. Also, EGF of 10 ng/ml was added immediately after 10 Gy irradiation. Cell growth was evaluated by counting the living cell number using a hemocytometer at 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Cell cycle arrest and apoptosis induction were assayed with the flow cytometry at 8 hours, 12 hours, 1 day, 2 days, 3 days, 4 days and 5 days after irradiation. Results : Growth of irradiated three cell lines were inhibited in proportion to radiation dose. EGF treatment after irradiation showed various results according to cell lines. On all cell lines, G2 arrest was detected after 8 hours and maximized after 12 hours or 1 day. Amount of G2 arrest was positively dose dependent. However, EGF showed no significant change on G2 arrest. G2 arrest was recovered with time at 2 Gy and 5 Gy irradiation. However, at 10 Gy irradiation, G2 arrest was continued. Apoptosis was detected at 10 Gy irradiation. On EGF treated group after irradiation, A431 and Siha cell lines showed slightly increased apoptosis but there was no statistically significant difference. KB cell line showed no marked change of apoptosis induction. Conclusion : Irradiation effects on cell cycle arrest and apoptosis induction in three human epithelial tumor cell lines, however epidermal growth factor doesn't effect on.

• 한국축산식품학회지
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• 제26권4호
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• pp.471-477
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• 2006

본 연구는 사막이나 우주 등 극한 환경에서도 취식이 가능한 즉석 양념 돼지 갈비 구이의 저장 안정성 확보를 위한 고선량 조사 적용을 평가하기 위해 실시하였다. 이를 위해 즉석 양념 돼지 갈비 구이를 제조하여 진공 포장한 후 10, 20, 30, 40 및 50 kGy로 조사하고 $35^{\circ}C$에서 가속 저장하면서 미생물 생육과 지질 산패도를 평가하였다. 가열처리에 의해 약 3 Log CFU/g의 미생물 감소 효과를 얻을 수 있었으나, 완전 사멸시키지는 못했다. 감마선 조사에 의해 저장 초기 미생물 생육은 관찰되지 않았으나, 저장 기간이 경과함에 따라 10, 20, 30 kGy조사구에서 저장4일, 7일, 14일에 미생물 생육이 관찰되었다. 오염 미생물의 최대성장률 예측 결과에서 비조사구, 10, 20, 30 kGy 감마선 조사구의 최대 성장률이 1.13, 0.60, 0.52, 0.18 Log CFU/g/day로 나타나, 감마선 조사에 의한 초기 미생물 감소가 저장성 증진에 크게 효과적인 것으로 판단되었다. 그러나 가속 저장 중 malondialdehyde 함량은 저장 기간이 경과함에 따라 모든 처리구에서 증가하였고, 특히 감마선 조사에 의해 심한 지질 산화가 발생되는 것으로 나타났다. 따라서, 고선량 조사 적용시 품질 변화 없이도 육가공품의 완전멸균을 위해서는 다양한 식품 가공 방법과의 병용 처리 연구가 수행되어야 할 것이다.

• 대한수의학회지
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• 제39권3호
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• pp.628-634
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• 1999

We have studied, by a nonisotopic in situ end-labeling(ISEL) technique, frequency of apoptosis in the external granular layer(EGL) of the cerebellum of immature mice by ${\gamma}$-rays irradiation from $^{60}Co$ or diagnostic ultrasound exposure. The total number of normal cells and cells showing morphological features of apoptosis were counted. The frequency of apoptotic cells was expressed as a percentage of the total number of cells in EGL. The extent of changes following 200 cGy(1090 cGy/min) was studied at 2, 4, 6, 8, 12, or 24 hours after exposure. The maximal frequency was found 6~8 hours after exposure. The immature mice that received 18, 36, 54, 108, 198, 396 cGy of ${\gamma}$-rays or diagnostic ultrasound(7.5MHz, 4.2mW, $I_{SPTA}=7.9mW/cm^2$, $I_{SPTA}=114.3W/cm^2$) for 10 or 30 minutes were examined 6 hours after irradiation. Measurements performed after ${\gamma}$-ray irradiation showed a dose-related increase in apoptotic cells in each of the mice studied. The dose-response curves were analyzed by a linear-quadratic model ; frequency of apoptotic cell in the EGL was y = $(0.1349{\pm}0.01175)D$+$(-0.0001522{\pm}0.0000334)D^2$+0.048($r^2$ = 0.981, D = dose in cGy). In the experiment of ultrasound exposure, the frequency of apoptotic cell was $0.106{\pm}0.130$(10 minutes exposure) and $0.167{\pm}0.220$(30 minutes exposure). We estimated the relative dose of the yield from the experiment with ultrasound by substituting the yield from ultrasound exposure into the curve from the ${\gamma}$-irradiation. The relative dose of ultrasound exposure compared with ${\gamma}$-irradiation were 0.432 cGy(10 minutes exposure) and 0.885 cGy(30 minutes exposure). We have found that there is no evidence to indicate that diagnostic ultrasound involves a significant risk.

• 한국식생활문화학회지
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• 제15권4호
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• pp.279-285
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• 2000

A survey was conducted to examine the effect of food irradiation education on college students' knowledge and acceptance of food irradiation. The instrument for the knowledge and acceptance of food irradiation was administered before and after food irradiation education, to 150 students majoring in food and nutrition or food technology in the Chungnam National University. Before the education approximately 93% of the respondents did not know that radioactivity dose not remain in food after irradiation; whereas, after education half of them thought that radioactivity dose not remain in irradiated food. Knowledge about food irradiation has improved through education. The education significantly increased all the mean scores of need for food irradiation and willingness to use irradiated foods for the six food groups (p<0.01). The education significantly decreased the mean scores of concern about the irradiated food for all the six food groups (p<0.01). Although the responses to irradiated foods are, in general, negative or neutral even after education, the mean scores of acceptance of the irradiated foods have improved through education in all the six food groups (p<0.01). In conclusion, this study showed that food irradiation education may positively affect the college students' knowledge and acceptance of food irradiation, and that the development of both the appropriate detection methods to identify irradiated foods and the education programs to enlighten the college students are needed.