• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.777-781
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• 2001

The effects of gamma-irradiation on the nutritional components of some Korean soybean-based fermentation foods were studied. Doenjang (soybean paste), kochujang (red pepper paste) and chungkukjang were prepared, irradiated at 0, 5, 10 and 20 kGy, and their compositions of free amino acid, free fatty acid and organic acid were determined. Compositions of free amino acid and free fatty acid in gamma irradiated sample were stable compared to non-irradiated control. Content of citric acid and succinic acid increased, while that of malic acid decreased in the gamma irradiated chungkookjang, but there were no significant changes in organic acid composition in organic and kochujang.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.295-301
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• 1998

Potential applications of irradiation technology inpostharvest handling of agricultural products have been documented over the past five decades. The biological effects of ionizing radiation on food were demonstrated to have the potential both of reducing the storage losses by controlling spoilage microoraganisms, insects, to have the potential both of reducing the storge losses by controlling spoiliage microorganisms, insects, sprouting and ripening, and of improving the hygienic quality of raw and processed products. Food irradiation is recognized as a physical and cold process using gamma-rays from radioisotope sources and electron-beam from the accelerator. As one of the technologies or techniques for preserving and improving the safety of food, irradiated technology has been approved in some 40 countries for more than 200 individeual items of foods and of these about 30 countries including Korea are commerically utilizing this technology. Although limited quantities of irradiated foods are available in the market now, the proper uses of this renewed technology will offer great possibilities not only for increasing the availability of postharvest agricultural products, thereby contributing to price stabilization in the off-season, but also for reducing reliance on chemicals used for sanitary and quarantine requirements. This paper deals with biological actions of ionizing radiation and its potential applications in the agri-food industry from the international point of view.

• Food Science and Preservation
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• v.4 no.1
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• pp.17-25
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• 1997

The effects of microwave treatment on the perservation of foods, such as a seaweed soup and sea stoned radish shreds, were studied. Microwave treatment of microbial cell suspensions revealed that viable cells decreased dramatically when heated to 6$0^{\circ}C$. However, it was unlikely that microwave treatment to 60 is enough to decrease the viable cell counts efficiently in a seaweed soup and radish shreds. It was thought that microwave heating to at least 7$0^{\circ}C$ as a final temperature was an important factor to reduce microbial cell counts in foods. When foods were heated to 7$0^{\circ}C$ with a repetitive 15 sec "on" followed by 30 sec "off", no big differences were observed in viable counts during storage at 2$0^{\circ}C$ for 3 days, as compared to those treated with a full power. The microwave treatment with three stages was designed to solve problems associated with variations depending on food volumes and difficulties of heat diffusion in a solid food to be irradiated with a microwave oven. The three stage method was found to have a similar efficiency in the reduction of viable cell counts in foods to microwave treatment at a full power and to conventional methods, such as water bath heating or boiling for 3 min with a gas range.in with a gas range.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.7-14
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• 2013

In this study, we investigated the applicability of the photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) methods for various foods. The analysed samples consist of 11 items including dried fruits (6 items) and mushrooms (5 items). To compare between non-irradiated and irradiated food, all samples were irradiated with $^{60}Co$ gamma-ray source. In PSL study, the photon counts of all the unirradiated sample were identified negative (lower than 700). The photon counts irradiated (1, 5, 10 kGy) dried date-palm, dried jujube and mushrooms (Auricularia auricula, Phellinus linteus and Sarcodon aspratus) showed positive (higher than 5,000) and the results for the other samples were negative or intermediate (>700 and >5,000). In TL analysis most of items can be applicable to detect irradiated foods because of showing TL ratio above 0.1. The glow curves by TL method were estimated in the range of $150{\sim}250^{\circ}C$ in irradiated samples. In ESR measurements, the intensity of ESR signal (single-line) increased as the dose of irradiation increased. In particular, the specific ESR signals of irradiation-induced radical were detected in dried papaya, dried date-palm, dried banana, dried pineapple and S. aspratus. According to the results, PSL, TL and ESR methods were successfully applied to detect the irradiated foods. It is concluded that PSL, TL and ESR methods are suitable for detection of irradiated samples and a combined method is recommendable for enhancing the reliability of detection results.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.297-303
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• 2011

The purpose of this research is to detect whether agricultural products were electron beam irradiated or non-irradiated by chemical methods according to increase of storage period. The three fat-rich samples including soybean, walnut, and sesame were chosen as agricultural products, and then were irradiated with doses of 1~10 kGy by using 10 MeV electron beam facility. At the result, 8-heptadecene and 1,7-hexadecadiene, which are indicators of electron beam-irradiation in chemical methods by gas chromatography/mass spectrometry(GC/MS) method, were detected in all three samples. The levels of two irradiation indicators were increased by electron beam-irradiation in a dose-dependent manner. Furthermore, two irradiation indicators also were detected in all samples in 6 and 12 months after irradiation, though levels of those were decreased in a time-dependent manner. These results mean that the quantification of 8-heptadecene and 1,7-hexadecadiene could determine whether electron beam were irradiated or non-irradiated until 12 month after irradiation in 3 fat-rich agricultural products including soybean, walnut, and sesame.

• Journal of Food Hygiene and Safety
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• v.1 no.1
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• pp.107-113
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• 1986

It is estimated that the loss of Korean agricultural and fishery products during the storage period is usually more than 20%, and it is difficult to increase agricultural products by a 10% annual rate directly. Therefore, development of food preservation techniques has now become a most important atternative for the indirect increase of such products and for its senitary distribution. Changes eating habits and improved living conditions have accelerated the demand for convenience food production and for this reason it is essential that raw materials at stable, resonable prices and hygienic quality be available the year round. At the end of 1980, the Korean government conceded th economical feasibility of the storage of foods by irradiation and a procedure for preserving food by irradiation on a batch scale was successfully developed by KAERI in 1982. Based on the research results accomplished by the KAERI and on the recommendation on wholesomeness of irradiated food by Joint Committee of FAO/IAEA/WHO in 1980, the approval of wholesomeness of irradiated food was declared by presidential decree in June 1985 and the procedure of permission for individual items is in progress. Korean private firms (Ryung Young Co.) which was technically assisted by KAERI for five years have taken mush interest in the establishment of such facilities in Korea, therefore Ryung Young Co. had proposed for the construction of 500 Kci Co-60 irradiator to the Ministry of Science and Technology in July 1984. The permission of construction has approved by government in May 1985. The commercial irradiator will be constructed as one of the most modernized facilities until May 1987 and that facilities will contribute the propagation of commercial storage of foods and its hygienic quality.

• Journal of the Korean Society of Food Culture
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• v.14 no.4
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• pp.289-304
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• 1999

The purpose of this study was to examine the consumers' acceptance of irradiated foods according to sociodemographic characteristics and the factors to distinguish subjects with differential levels of their willingness to buy them. Data were collected from the 365 women living in Youngnam area by the self-administered questionnaire. The results from this study were as follows. First, consumers were concerned regarding food safety issues in general and particularly preservatives. Second, many subjects had not heard of the irradiated foods and showed wait-and-see attitude in the willingness to accept them. Consumers' willingness to purchase them were higher than any other cases if radiation would not remain in foods. Third, the results from the discriminant analyses showed that the concern toward food safety, perceived innovativeness, willingness to pay more for organic foods, and knowledge of irradiation were the factors to distinguish groups with differential levels of willingness to purchase the irradiated foods. The results from the study imply that accurate and scientific information about food irradiation should be given to the consumers.

• Journal of Food Hygiene and Safety
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• v.25 no.1
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• pp.73-78
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• 2010

This research was conducted to assess applicability of photostimulated luminescence (PSL) and Thermoluminescence (TL) methods for investigation of infant and young children products, nut, seasoned dried fish, spice, dried fruits, fruit & vegetable, grain and marine products, which are not approved for irradiation in Korea. PSL results show that the photon counts of non-irradiated samples were lower than 700, while those of irradiated samples were higher than 700. In TL measurement, TL ratio of irradiated samples were higher than 0.1 or ones can decrease below 0.1 whereas the temperature range of TL Glow curve was between $150{\sim}250^{\circ}C$. Monitoring result about 8 class of 325 not approved to irradiated foods, photon counts of samples were less than 700, and after re-irradiation TL Ratio ($TL_1/TL_2$) through re-irradiation step at 1 kGy were higher than 0.1 for the all samples. Therefore, these results suggested that PSL and TL measurements were useful detection methods for 8 class food products not approved to irradiation in Korea and all sample (325 cases) were not irradiated when we analysed by PSL and TL methods.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.129-138
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• 2004

The changes in DNA damage were investigated during storage after irradiation. Beef, pork and chicken were irradiated at 1.0, 3.0 and 5.0 kGy and stored for 6 months at $-20^{\circ}C$. The comet assay was applied to the sample muscles at the beginning of irradiation and at the end of storage. Muscles were isolated, sliced, and the suspended cells were embedded in an agarose layer. After lysis of the cells, they were electrophoresed for 2 min. and then stained. DNA fragmentation in tissues caused by irradiation was quantified as tail length and tail moment (tail length ${\times}$ % DNA in tail) by comet image analyzing system. Right after irradiation, the differences in tail length between unirradiated and irradiated muscles were significant(p<0.05) in beef, pork and chicken. With increasing the increasing doses, statistically significant longer extension of the DNA from the nucleus toward anode was observed. Similarly even 6 months after irradiation, all the irradiated muscles significantly showed longer tail length than the unirradiated controls. The results represented as tail moment showed similar tendency to those of tail length, but the latter parameter was more sensitive than the former. These results indicate that the comet assay could be one of the simple methods of detecting irradiated muscles. Moreover, this method suggest that using comet assay, we were able to detect DNA damage differences even after 6 months after irradiation.

• Journal of Radiation Industry
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• v.4 no.3
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• pp.233-237
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• 2010

This study evaluated the change in whitening activity of ${\beta}-glucan$ by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 100 kGy irradiated ${\beta}-glucan$. Melanin synthesis of irradiated ${\beta}-glucan$ was measured from B16BL6 melanoma cell line treated with ${\alpha}-melanin$ stimulating hormone. Melanin synthesis was increased in the ${\alpha}-melanin$ stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated ${\beta}-glucan$ treated with ${\alpha}-melanin$ stimulating hormone. These results indicate that gamma irradiated ${\beta}-glucan$ may elevate the whitening activity. Therefore, gamma-irradiated ${\beta}-glucan$ could be used for nutraceutical foods in cosmetic industry.