• Nuclear Engineering and Technology
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• v.29 no.6
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• pp.500-507
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• 1997

The development of detection techniques is needed, in order for regulating authorities to determine whether or not a particular food sample has been irradiated, and label it accordingly so that a consumer's free choice can be exercised. The chemical and physical changes brought about in foods by practical doses of irradiation are very small, and therefore very sensitive methods are required. A number of promising approaches have been developed and evaluated. These include chemical, physical and biological methods ranging from the very simple to highly sophisticated techniques.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.423-426
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• 2001

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose on irradiated dried fruits. Dried banana, pineapple and pistachio were irradiated with doses of 0, 0.5, 1, 2 and 5 kGy at room temperature using a Co-60 irradiator. Multiplet ESR signals were observed in irradiated dried banana and pineapple, and singlet ESR signal was observed in irradiated pistachio, while these characteristic signals were not detected in non-irradiated samples. Since the amount of free radicals linearly increased with the applied doses $(0.5{\sim}5\;kGy)$, highly positive correlation coefficients $(R^2=0.9874{\sim}0.9974)$ were obtained between the irradiation doses and the corresponding free radical concentrations. The characteristic ESR signals were observed in irradiated samples even after 40 days of storage at room temperature.

• Journal of Nutrition and Health
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• v.36 no.3
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• pp.255-261
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• 2003

Food irradiation has been steadily increasing in many countries in line with increasing international trade and concerns about naturally occurring harmful contaminants in food. Although irradiation provides an excellent safeguard for the consumer by destroying almost 100% of harmful bacteria, it is necessary to ensure the safety of irradiated foods. This study was performed to investigate the effect of an irradiated diet on lipid peroxidation in the plasma, liver, small intestinal mucosa, and lymphocyte DNA damage in mice. Eight-week old ICR mice were assigned to two groups to receive either non-irradiated or irradiated (10 kGy) diets containing 20.38% fish powder and 6.06% sesame seeds for 4 weeks. The resulting changes in the degrees of lipid peroxidation were evaluated based on the level of plasma and liver thiobarbituric acid reactive substance (TBARS), transmission electron micrograph of jejunal mucosa, and free radical-induced oxidative DNA damage in lymphocytes, as measured by alkaline comet assay (single cell gel electrophoresis). The peroxide values of the gamma irradiated diet were measured every week, and the sample for comet assay was taken at the end of the four week experimental period. There was no significant difference in food efficiency ratio between the two groups. The peroxide values of the diet were immediately increased to 35.5% after gamma irradiation and kept on increasing during storage. After 4 weeks, no differences in tissue or plasma TBARS value were observed between the two groups, but epithelial cells of jejumum showed osmiophillic laminated membranous structures, considered as myelin figures,. The oxidative DNA damage expressed as tail moment (TM) increased 30% in the blood lymphocytes of the mice fed the irradiated diet. In conclusion, the comet assay sensitively detected differences in lymphocyte DNA damage after feeding with the irradiated diet for 4 weeks. However, in order to ensure the safety of irradiated foods, it would be more useful to conduct a long-term feeding regimen using an irradiated diet and examine the level of lipid peroxidation and the state of oxidative stress in a greater range of organs.

• Journal of Food Hygiene and Safety
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• v.16 no.2
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• pp.133-138
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• 2001

Toxicological safety on 20 kGy-gamma irradiated Kanjang (soy sauce), Doenjang (soybean paste), Kochujang (hot pepper paste) and Chunghukjang (soy paste) was determined by SOS Chromotest. As the strain of the SOS Chromotest, Escherichia coli PQ37 was used in the condition of presence or absence of an exogenous metabolizing system (S-9 mix). Water extract or organic solvent extract was prepared from samples, concentrated and tested by SOS Chromotest with S-9 mix or not. All irradiated samples were not different from non-irradiated one in the bacterial assay maintaining the below 1.5 of IF(induction factor) values in the adapted dose of 10,000$\mu\textrm{g}$/assay. The results indicated that any mutagenicity was not observed in 20 kGy-irradiated traditional soybean fermented foods.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.57-61
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• 2002

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated dried seasoning powder. Seasoning powders of dried squid flavor, shrimp flavors, kimchi flavor, spicy beef soup flavor and soy sauce flavor were irradiated with doses of 0, 1, 3, 5, 7 and 9 kGy at room temperature using a Co-60 irradiator. Characteristic signals of free radicals were observed in all the irradiated samples of this experimental while these signals were not detected in non-irradiated samples. Since the free radical concentrations linearly increased with the applied doses (1~9 kGy), highly positive correlation coefficients ($R^2$ = 0.9285~0.9965) were obtained between irradiation doses and free radical concentrations during all the storage times. Free radical concentrations of the irradiated flavored seasoning powder did not change even at 16 weeks of storage at room temperature, while those of dried squid, shrimp and spicy beef soup flavors decreased until 2 weeks of storage after irradiation with 5 kGy or over, and these of soy cause flavors slowly decreased until 8 weeks of storage after irradiation with 3 kGy or over. Although the free radical concentrations decreased with storage times, the characteristic signals of the irradiated seasoning powders of dried squid, shrimp, spicy beef and soy sauce flavors were observed even after 16 weeks of storage at room temperature.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1588-1593
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• 2014

This study evaluated the genotoxic effects of 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper). In bacterial reversion assay with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, the X-ray irradiated foods did not show a significantly increased number of revertant colonies in the presence or absence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, the X-ray irradiated foods showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, the X-ray irradiated foods did not show any increase in the frequency of polychromatic erythrocytes with micronuclei. These results indicate that 30 kGy of X-ray irradiation to four foods (chicken, egg powder, dried green onion, and black pepper) showed no genotoxic effects under these experimental conditions.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.136-141
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• 2000

The properties of pulsed photostimulated luminescence (PPSL) were measured to use as basis data for the detection of irradiated foodstuffs (34 different foods). Samples were packed in polyethylene bags and irradiated at 1, 5, and 10 kGy with a dose rate of 10 kGy/h. The samples irradiated were introduced in the sample chamber without other preparation and measured PPSL photon counts for 60 and 120 s. The PPSL photo counts of the irradiated samples were higher than the unirradiated, increased with increasing irradiation dose, and showed a good relationship between irradiation doses and photon counts in a multinomial expression. These results suggest that the detection of irradiated foodstuffs was possible by PPSL. Therefore, PPSL can be proposed as the method for the detection of irradiated foodstuffs.

• Journal of the Korean Society of Radiology
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• v.12 no.5
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• pp.603-614
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• 2018

This study aims to identify the awareness of radiation irradiation foods for radiologists, to help them understand the radiation irradiation foods properly, and to provide basic data on educational programs. The survey was conducted from February 1 to 28, 2018, with a survey of university students majoring in radiology at universities in Daegu and Gyeongbuk provinces. 73.7% of the respondents said that they did not have educational experience in radiological survey foods and related educational experiences. 49.8% of radiologists and 31.6% of school education were the most effective methods of radiation survey foods. As for the intention to participate in education on radiation irradiated foods, 54.5% of the respondents said that they are "normal" and that the participation rate of the students can be increased when providing education on radiation irradiated foods. As for when it is appropriate to conduct education on radiation-invested foods, 27.7% from 'Elementary School' and 23.0% from 'Middle School' are shown. Considering the above results, it is deemed necessary to develop specific promotional activities and educational programs for the overall recognition and clear understanding of irradiated food products of college students who are sensitive to diet.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.498-501
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• 1998

It was determined whether photostimulated luminescence (PSL) is applicable to the detection of post-irradiation of foods by measuring PSL photon counts for unirradiated and irradiated pepper powder, dried herbs, fresh shrimp, potato, soybean, dried fig, chestnut, dried squid, and dried cod. The samples were irradiated with $^{60}Co\;{\gamma}-ray$ source and PSL photon counts were measured for them. The photon counts of unirradiated samples were lower than 2,000 for potatoes and less than 1,000 for the others. The photon counts of the irradiated samples except dried figs (0.5 kGy), chestnuts (0.2 kGy), and dried squid (0.5 kGy) were higher than 1,000, and the photon counts increased with dose. Thus, PSL might be applied to the primary detection of irradiated foods.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.79-84
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• 1985

This research was attempted in order to develop a long-term storage method for sprouting foods such as potatoes, onions, garlic and chestnuts using Co-60 gamma irradiation combined with a natural low temperature. The sprouting of the irradiated groups, 150 Gy in potatoes, 50 Gy in onions and garlic, and 250 Gy in chestnuts was almost completely inhibited until 8 to 10 months of storage. The rotting rate of loss of weight influenced a little by irradiation with a sprout inhibiting dose, and the weight of loss of the optimum dose irradiated groups was reduced by about 6 to 24% as against that of the nonirradiated in the four stored foods. The chemical components relating to the quality of sprouting foods were better retained in the irradiated groups than in the nonirradiated until the latter period of storage. Therefore, it was shown that the long term storage of sprouting foods is possible using gamma irradiation of 50 to 150 Gy for potatoes, onions, and garlic and 250Gy for chestnuts followed by storage at a natural low temperature($10{\pm}5^{\circ}C$, R.H. 75-85%).