• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.186-191
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• 1985

The effect of gamma irradiation on the physicochemical properties of chicken meat and its sensory quality were investigated during 41 days of storage at 3 to $4^{\circ}C$ following irradiation of 5 to 10 kGy. Immediately after irradiation, the water holding capacity of chicken meat decreased slightly with the increase of irradiation dose, whereas during storage, the water holding capacity of irradiated groups was superior to that of the nonirradiated ones. With increasing the irradiation dose and storage time, the TBA values of irradiated groups were higher than those of nonirradiated ones. The volatile basic nitrogen content of nonirradiated group markedly increased over 20mg% by microbial spoilage from the 10th day of storage, however, the irradiated groups of over 8 kGy showed only the 16 to 18mg% until 41 days of storage. The irradiated groups had a slight irradiation-odour that dissipated during up to 3 days of storage, and also they showed a slight pink discoloration in the carcasses and this tendency was much more pronounced with increasing irradiation dose. The nonirradiated group gave off an off-odour due to the spoilage around 5 to 7 days of storage and showed a change in meat appearance, while the irradiated groups of over 5 kGy maintained a fresh state during the 25 to 30 days of storage.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.256-261
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• 2014

This study was conducted to determine the effect of gamma-ray and electron-beam irradiation on dried spices (black pepper, red pepper, parsley, and basil) using the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods. The spices were irradiated at 0, 1, 5, and 10 kGy. All non-irradiated spices had photon counts (PCs) less than 700 PCs. The PCs of three irradiated spices (red pepper, parsley, and basil) were clearly distinguishable from those of non-irradiated ones, exhibiting PSL signals higher than 5000 PCs. However, negative PSL counts (<700 PCs) were obtained for most irradiated black pepper, except those irradiated with 5 kGy gamma rays and 10 kGy electron-beams. TL glow curves of the irradiated spices showed a higher peak at $150-250^{\circ}C$. TL ratios were found to be less than 0.1 for non-irradiated spices and higher than 0.1 for irradiated ones. No ESR signal was observed for any irradiated spice except red pepper, which displayed cellulose-based ESR spectra. Therefore, the results suggest that the PSL, TL, and ESR methods are effective detection techniques for dried spices irradiated with electron beams as well as gamma rays.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.116-121
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• 1983

A study was conducted to evaluate the effect of $^{60}CO-{\gamma}$ irradiation on the preservation on Satauma mandarin in Cheju Island. Four varieties (S. m. early, S. m. Komezawa, S. m. Hayashi and S. m. Aoshima) were irradiated using 10,000Ci, $^{60}CO-{\gamma}$ ray with dosages of 0, 50, 100 and 150Krad. During 92 days of storage the effects of irradiation on mandarin porperties were as follows: At the end of storage period the accumulated fruit rotting percentage were S. m. Komezawa($T_2$);74.32%, S. m. early($T_1$);69.67%, S. m. Aoshima($T_4$);64.33% and S. m. Hayashi ($T_3$);61.79%. The rottings steadily increased from the early stage of storage and rapid spoilage continued after 59 days of irradiation. A high corelation existed between fruit rotting and varieties ($T_3$;Y=0.78x-15.30, $T_4$;Y=0.79x-12.29, $T_1$;Y=0.93x-9.01 and $T_2$;Y=0.79x-13.49) High dosages(100 and 150 Krad)improved fruit preservation during the mid storage stage. However 76 days after high dose irradiation there was no significant difference a rotting between irradiated fruit and the control. Irradiation decreased acidity of fruit during storage (p<0.01). The mean acidities of examined varieties were $T_1$;1.01%, $T_3$;1.01%, $T_4$;0.84% and $T_2$;0.77%. A significant differences were observed in acidity between varieties and dosages(P<0.01) With one exception in all treatments. the increase in free and total sugar content was not statestically significant. The exception was the 50 Krad treatment where the total sugar content decreased. $T_1$ and $T_4$ showed slightly higher value of than Brix $T_2$ and $T_3$, and were significantly(P<0.01) decreased by higher dosage. The ascorbic acid content in all treatments decreased with length of storage and also decreased significantly with a higher dosage.

• Korean Journal of Environmental Agriculture
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• v.23 no.1
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• pp.52-58
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• 2004

This work was conducted to provide the reference data of radioactivity in the foodstuffs at a radiological emergency situation in Jeju Island The sampled foodstuffs were agricultural (31), livestock (6), marine (12) and forest products (4), and processed foods (3) consumed by Jeju Islanders. $^{137}Cs$ and $^{40}K$ activities were determined by HPGe r-ray spectromety. The activity ranges of $^{137}Cs$ was ${\sim}650\;mBq/kg$ fresh in the agricultural products, ${\sim}131\;mBq/kg$. fresh in the livestock, ${\sim}834\;mBq/kg$ fresh in the forest, ${\sim}253\;mBq/kg$ fresh in the marine and $32.0{\sim}483\;mBq/kg$. fresh in the processed foods (tea). In case of $^{40}K$ the activity was $16.6{\sim}542\;Bq/kg$. fresh in the agricultural products, $39.1{\sim}294\;Bq/kg$ fresh in the livestock, $85.5{\sim}116\;Bq/kg$ fresh in the forest, $50.1{\sim}657\;Bq/kg$ fresh in the marine, and $33.6{\sim}1,065\;Bq/kg$ fresh in the processed foods (tea). The highest activity of $^{137}Cs$, 834mBq/kg fresh was observed in oak mushroom and $^{40}K$ 1,065 Bq/kg fresh in coffee. Annual effective doses of $^{137}Cs$ and $^{40}K$ by intake of foodstuffs per capita were the following order; agricultural products (66,543 nSv) > livestock products (19,311 nSv) > processed foods (6,648 nSv) > marine products (6,579 nSv) > forest products (860 nSv). Therefore, total annual effective dose was summed 99,941 nSv which is quite low level comparing to the annual effective dose by external exposure, 2,400,000 nSv. The data obtained in this study can be useful for monitoring whether the foodstuffs are contaminated or not at an emergency radiation accident, and showed that the foodstuffs consumed in Jeju are safe in terms of annual effective dose of $^{137}Cs$ and $^{40}K$

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.515-521
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• 2009

The DEFT (direct epifluorescent filter technique)/APC (aerobic plate count) test was utilized to screen powdered Ramen soup samples (RS-1, RS-2) whether or not they have been microbial-decontaminated. The initial microbial loads of commercially-packaged samples were log DEFT 6.46 (RS-1) and 7.05 (RS-2), but the viable bacterial counts were log APC 2.74 (RS-1) and 1.95 (RS-2), respectively; this finding showed that they have been already decontaminated by methods other than irradiation. The same samples were then subjected to gamma irradiation at 0, 5 and 10 kGy in order to evaluate the microbial and physicochemical changes during post-irradiation storage for 6 months under room conditions ($10{\pm}3^{\circ}C$). The DEFT count was constant in irradiated samples even at different doses, but APC decreased with dose increases; this implies that the log DEFT/APC increased in a linear fashion with dose. No coliforms, yeasts and molds were detected in any of the samples, whereas the initially detected aerobic bacteria ($5.49{\times}10^2CFU/g$) were inactivated by 5 kGy or more and no growth was observed during the subsequent storage period. The pH of RS-1 was reduced by irradiation (p<0.01), but increased (p<0.01) with increasing storage time. Irradiation induced a reduction in volatile basic nitrogen (VBN), whereas an increase in thiobarbituric acid (TBA) values was observed. The storage time proved more influential than irradiation up to 10 kGy in terms of changes in the VBN and Hunter’s color values of powdered Ramen soups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.909-915
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• 2014

This study was carried out to evaluate the genotoxicity of imported oranges irradiated with ionizing energy (0.5 and 1 kGy). In bacterial reversion assays with Salmonella Typhimurium TA98, TA100, TA1535, and TA1537, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no significant increase in the number of revertant colonies in both the absence and presence of the S9 metabolic activation system. In chromosomal aberration tests with Chinese hamster ovary (CHO) cells, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no increase in the frequency of chromosomal aberrations. In in vivo mouse micronucleus assay, imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no increase in the frequency of polychromatic erythrocytes with micronucleus. These results indicate that imported oranges irradiated with ionizing energy (0.5 and 1 kGy) showed no genotoxic effects under these experimental conditions.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.11-14
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• 2005

White radish was minimally processed, packed with air, $CO_{2}$ (100%), and $CO_{2}/N_{2}$ (25/75%), and irradiated at 0, 1, and 2 kGy, and its microbiological quality and pH were investigated during storage for 2 weeks at $4^{\circ}C$. Irradiation significantly reduced total aerobic, coli-form, and lactic acid bacteria counts. Modified atmosphere packaging (MAP) enhanced microorganism control during storage. Acidity decreased by MAP but was restored during storage, Irradiation did not affect sample pH. Results show irradiation at 2 kGy combined with MAP can enhance microbiological safety and quality of minimally processed radish.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.399-404
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• 2016

The applicability of photostimulated-luminescence (PSL) and thermoluminescence (TL) for the detection of 12 food materials (potato, onion, garlic, dried pumpkin, black mushroom, black soybean, Cheongkukjang powder, sea mustard, pepper powder, Ramyun soup, corn tea, and green tea powder) irradiated with an electron beam, gamma ray, and X ray at a range of 0.15 to 10 kGy was investigated. For PSL, negative results (less than 700 photon counts (PCs)) were observed from non-irradiated foods while the irradiated foods showed intermediate (879 to 2,414 PCs) and/or positive (19,951 to 65,919,035 PCs) values. In all irradiated samples, the maximum peak of the TL glow curve was observed between 150 and $250^{\circ}C$. Our findings demonstrate the successful application of PSL and TL to determine whether food items were irradiated or not. However, there were no significant differences among the radiation sources.

• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.7-14
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• 2016

Background: The objective of this study was to investigate Korean people's awareness about impact of the Fukushima nuclear power plant accident in Japan and radioactive contamination caused by it. Materials and Methods: The respondents of the survey were 600 adults who resided in the Seoul metropolitan area. Results and discussion: The survey results show that the majority of respondents were concerned about impact of radiation leakage that might have an effect on our environment. They were worried about radioactive contamination of foodstuffs, particularly fishery products and preferred to acquire information through TV(49.8%) or the Internet(31.3%). Meanwhile, respondents mentioned that the information on the Fukushima nuclear accident and radioactive contamination had not been sufficient and they didn't know well about the follow-up measures of the government on the accident. Most respondents answered that information on radioactive contamination levels and safety of foods and environment was most needed. Conclusion: The results of this study could be useful to enhance awareness on radioactivity and improve risk communication on nuclear power plant accidents.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.720-725
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• 2000

To reduce the antigenicity of egg white (EW), EW was treated with several proteolytic enzymes, trifluoromethanesulfonic acid (TFMS), heat, and NaOH. Competitive indirect enzyme-linked immunosorbent assay (ciELISA), using rabbit anti-EW antibody, was performed to examine the antigenicity of the treated EW's. Enzymatic hydrolysis gave no good effect on the reduction of the antigenicity of EW. Neither did the pretreatment with ${\gamma}-irradiation$ before the hydrolysis reduce the antigenicity. TFMS treatment removed the antigenicity of EW. The antigenicity of EW heated at $120^{\circ}C$ for 30 min or treated with NaOH at 0.3% (w/v) and more, decreased to less than 1/10,000 as compared with that of native EW. The combinatory treatment with NaOH, followed by heat at $70^{\circ}C$ for 15 min had a synergic effect on the reduction of the antigenicity of EW.