• 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.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.570-575
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• 2014

This study was conducted to compare the effects of two forms of radiation (electron and X-ray; generated by an electron beam accelerator) on the conformation and antigenic properties of hen's egg albumin, ovalbumin (OVA), which was used as a model protein. OVA solutions (2.0 mg/mL) were individually irradiated by electron beam or X-ray at the absorbed doses of 0 (control), 2, 4, 6, 8, and 10 kGy. No differences between the two forms of radiation on the structural properties of OVA were shown by spectrometric and electrophoretic analyses. The turbidity of OVA solution increased and the main OVA bands on polyacrylamide gels disappeared after irradiation, regardless of the radiation source. In competitive indirect enzyme-linked immunosorbent assay, OVA samples irradiated by electron beam or X-ray showed different immunological responses in reactions with monoclonal and polyclonal antibodies (immunoglobulin G) produced against non-irradiated OVA. The results indicate that electron beam irradiation and X-ray irradiation produced different patterns of structural changes to the OVA molecule.

• Food Science of Animal Resources
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• v.34 no.4
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• pp.464-471
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• 2014

Ground lean pork was irradiated by an electron beam or X-rays to compare the effects of two types of radiation generated by a linear accelerator on the quality of Bologna sausage as a model meat product. Raw ground lean pork was vacuum packaged at a thickness of 1.5 cm and irradiated at doses of 2, 4, 6, 8, or 10 kGy by an electron beam (2.5 MeV) or X-rays (5 MeV). Solubility of myofibrillar proteins, bacterial counts, and thiobarbituric acid reactive substance (TBARS) values were determined for raw meat samples. Bologna sausage was manufactured using the irradiated lean pork, and total bacterial counts, TBARS values, and quality properties (color differences, cooking yield, texture, and palatability) were determined. Irradiation increased the solubility of myofibrillar proteins in a dose-dependent manner (p<0.05). Bacterial contamination of the raw meat was reduced as the absorbed dose increased, and the reduction was the same for both radiation types. Differences were observed only between irradiated and non-irradiated samples (p<0.05). X-ray irradiation may serve as an alternative to gamma irradiation and electron beam irradiation.

• Journal of Radiation Industry
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• v.8 no.1
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• pp.1-5
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• 2014

This study investigated the reduction of microbial population and sensory properties in red pepper powders irradiated by gamma ray, electron beam, and X-ray. Populations of total aerobic bacteria and yeast & molds in red pepper powders were decreased by irradiation treatment in a dose-dependent manner. Gamma ray, electron beam, and X-ray at doses above 8 kGy caused 100% inhibition on growth of aerobic bacteria in red pepper powders. Inhibitory activity of X-ray on sterilization of red pepper powders was significantly equal to or higher compared to gamma ray and electron beam. Color and off flavor in red pepper powders were no significant difference among the control and samples irradiated with gamma ray, electron beam, and X-ray. As a result, the gamma ray, electron beam, and X-ray irradiation can be used to sterilize the microbial growth in red pepper powders without quality loss.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.109-116
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• 2016

This study evaluated the effects of low-dose X-ray irradiation treatment on quality characteristics and sensory evaluation of imported navel oranges during storage at $20^{\circ}C$ for 12 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, and changes in color value, hardness, Brix/acid ratio, total sugar content, reducing sugar content, vitamin C content, and sensory evaluation were investigated. There were no significant differences between non-irradiated and irradiated samples in terms of color value, Brix/acid ratio, total sugar content, reducing sugar content, and vitamin C content. Difference in hardness between non-irradiated and irradiated samples decreased at the end of storage. Reducing sugar content was reduced as storage period increased. The sensory evaluation scores of non-irradiated and irradiated samples were not significantly different according to storage period, except for sweetness and texture. Overall acceptability was not significantly different by irradiation dose or storage period. These results suggest that X-ray irradiation does not affect quality characteristics or sensory evaluation.

• Journal of Ginseng Research
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• v.37 no.4
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• pp.483-490
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• 2013

Gamma-irradiation (0-7 kGy) of ginseng is permitted in Korea for the purpose of microbial decontamination; with strict labeling, traceability and monitoring requirements. An identification study was conducted to determine the photostimulated-luminescence (PSL) and thermoluminescence (TL) properties of gamma-irradiated fresh and white ginsengs cultivated in different areas. Dose- dependent PSL-based screening was possible for white ginseng samples; however, inappropriate results from non-irradiated fresh ginseng samples were obtained, showing intermediate (700 to 5,000) or positive ($T_2$ >5,000, irradiated) PSL counts due to the abundance of minerals on the surfaces of the samples. TL analysis of separated minerals from all non-irradiated samples gave TL glow curves of low intensity with a maximum peak after $300^{\circ}C$. However, well-defined irradiation-specific (high intensity with a maximum peak at about $200^{\circ}C$) glow curves were observed for all the irradiated samples, regardless of their type and origins. TL ratios (first glow curve /second glow curve) were also determined to confirm the irradiated (>0.1) and non-irradiated (<0.1) results. SEM-EDX (scanning electron microscope-energy dispersive X-ray) and XRD (X-ray diffraction) spectroscopic analyses showed that feldspar and quartz minerals were the main source for the typical radiation-specific luminescence properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.247-254
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• 2016

This study evaluated the effects of low-dose X-ray irradiation treatment on quality characteristics and sensory evaluation of imported navel oranges during storage at $3^{\circ}C$ for 45 days. The samples were irradiated at doses of 0.2, 0.4, 0.6, 0.8, and 1.0 kGy, and changes in their color value, hardness, Brix/acid ratio, total sugar content, reducing sugar content, vitamin C contents, and sensory evaluation were investigated. There was no significant increase or decrease in Brix/acid ratio, total sugar content, reducing sugar content, or vitamin C content between the non-irradiated and irradiated samples. Color value of orange peels decreased with increasing levels of irradiation treatment. Color b value of orange pulp increased with an increase in irradiation dose. Difference in hardness between the non-irradiated and irradiated samples decreased at the end of storage. For the sensory evaluation after 30 days, sweetness and overall acceptability of irradiated samples at more than 0.6 kGy were low. These results suggest that X-ray irradiation under 0.6 kGy does not affect quality characteristics and sensory evaluation.

• 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.

• Food Science and Preservation
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• v.21 no.3
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• pp.315-320
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• 2014

This study evaluated the effects of a gamma ray (GR), electron beam (EB), and X-ray (XR) to improve the safety of black pepper powder. The black pepper powder was irradiated by GR, EB, and XR at 2, 4, 6, 8, and 10 kGy. The results of the total bacterial populations in the black pepper power sample showed a similar effect on microbial decontamination for radiation sources. Radiation sensitivity ($D_{10}$ value) on the initial bacteria loads in the sample was 2.24 kGy in GR, 2.37 kGy in EB, and 2.75 kGy in XR. In addition, there were no differences among the radiation sources. The color values, such as L (lightness), a (redness), and b (yellowness), were not changed significantly. The sensory characteristics of GR, EB, and XR irradiated black pepper powder were decreased when the radiation dose increased, but there was no significant changes among the radiation sources. The results can be applied to investigate the effects of radiation sources on the microbiological and sensory characteristics of black pepper powder.

• Journal of Radiation Industry
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• v.8 no.2
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• pp.83-88
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• 2014

Application of X-ray irradiation of dried condiments was studied using commercially prepared dried garlic, onion and welsh onion flakes as model samples. Total load of aerobic microbes (TAM), color differences, and generation of off-flavor were quantified for samples individually irradiated with gamma rays, electrons, or X-rays. TAM load was decreased by irradiation in a dose-dependent manner. The three types of radiation did not differ in the extent of TAM reduction (P>0.05). The samples did not differ in color. Off-flavor was detected from 6 kGy-irradiated samples, regardless of radiation sources. The results indicated that X-ray irradiation could be used for irradiation of dried condiments with the same effects as gamma rays and an electron beam.