• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.111-116
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• 1997

For the purpose of improving hygienic quality of dried-Angelica Keiskei Koidz powder, the effect of ozone treatment and gamma irradiation on the microbial decontamination and physicochemical properties were investigated. Gamma irradiation at 5 to 7.5 kGy resulted in sterilizing total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the total aerobic bacteria of the sample. The physicochemical properties of the sample were not changed by gamma irradiation up to 7.5 kGy, whereas, ozone treatment caused remarkable changes in pH, TBA value, chlorophyll, carotenoid and fatty acid compositions. Therefore, this investigation demonstrated conclusively that gamma irradiation was more effective than ozone treatment for decontaminating and sterilizing the dried-Angelica Keiskei Koidz powder, with minimal effect on the physicochemical properties analyzed.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.344-347
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• 2006

This study evaluated the use of electron beam irradiation for decontamination of the Korean medicinal herb, Angelica gigas Nakai. Herb samples were irradiated at doses of 2, 8, and 16 kGy, respectively. Populations of microorganisms in Angelica gigas Nakai decreased by 2$\sim$3 log cycles at 8 kGy irradiation. Electron beam irradiation caused negligible changes in Hunter color L, a, and b values. Sensory evaluations of Angelica gigas Nakai confirmed that irradiation caused no significant changes in the organoleptic properties of the samples. These results suggest that electron beam-irradiated herbs retain a better microbial safety and sensory qualities, compared with the non-irradiated.

• 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.

• Food Science of Animal Resources
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• v.44 no.1
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• pp.19-38
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• 2024

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

• Safe Food
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• v.4 no.4
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• pp.33-39
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• 2009

• Journal of Microbiology
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• v.43 no.6
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• pp.572-576
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• 2005

This study focused on detecting catabolic genes for polycyclic aromatic hydrocarbons (PAHs) distributed in the reed rhizosphere of Sunchon Bay, Korea. These marsh and mud environments were severely affected by human activities, including agriculture and fisheries. Our previous study on microbial roles in natural decontamination displayed the possibility that PAH-degrading bacteria, such as Achromobacter sp., Alcaligenes sp., Burkholderia sp. and Pseudomonas sp. play an important decontamination role in a reed rhizosphere. In order to gain further fundamental knowledge on the natural decontamination process, catabolic genes for PAH metabolism were investigated through PCR amplification of dioxygenase genes using soil genomic DNA and sequencing. Comparative analysis of predicted amino acid sequences from 50 randomly selected dioxygenase clones capable of hydroxylating inactivated aromatic nuclei indicated that these were divided into three groups, two of which might be originated from PAH-degrading bacteria. Amino acid sequences of each dioxygenase clone were a part of the genes encoding enzymes for initial catabolism of naphthalene, phenanthrene, or pyrene that might be originated from bacteria in the reed rhizosphere of Sunchon Bay.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.1-4
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• 2006

The biological qualities of green, black, and oolong teas were monitored by observing their microbial decontamination and insect disinfestation following gamma irradiation (0-10 kGy) and fumigation (MeBr or $PH_3$) during 6-month storage at room temperature. Plodia interpunctella Hubner was found as an important quarantine pest in teas used. In a comparative study, both treatments were found to be effective in disinfecting the stored samples. An irradiation dose of 5 kGy was sufficient to control all microorganisms related to the quality of teas, while fumigation with methyl bromide and phosphine showed no appreciable decontamination effect on the microorganisms. As a result, irradiation was found an effective alternative to fumigants for the improvement of biological tea qualities during storage.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.419-429
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• 2023

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

• Food Science and Preservation
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• v.2 no.1
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• pp.163-171
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• 1995

Organoleptic qualities were evaluated putting emphasis on flavor and color of white ginseng powders which were treated with ethylene oxide(EO) and gamma radiation(5, 10kGy) for microbial decontaminations. Immediately after treatments, there was no significant changes in the overall flavor and color of the samples between the nontreated control and both treatments. The color of even airtight-packaged samples, however, was changed(p<0.05) after 7 months of storage at 30$\pm$2$^{\circ}C$ when treated with EO and 10 kGy. These changes in color were confirmed by the instrumental determinations for the stored samples. Thus, it can be proposed that gamma Irradiation below 10kGy combined with airtight packaging is required for keeping the organoleptic quality of white ginseng powders for more than 6 months of storage.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.167-171
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• 1994

With a view to improving microbiological quality of spinach powder which is currently used for convenience food production, comparative efficacy of ethylene oxide(EO) fumigation and gamma irradiation was investigated by determining microbial populations and physicochemical quality for treated samples. Spinach powder was contaminated with various microorganisms ranging from $10^{2}/g\;to\;10^{4}/g$, which composed of thermophiles, acid tolerant bacteria, fungi, coliforms, etc. Microorganisms contaminated were destroyed up to undetected levels by gamma irradiation at below 7 kGy. showing the radiosensitivity $D_{10}$ 2.93 kGy on total aerobic bacteria. Ethylene oxide fumigation, however. was found unsatisfactory for physicochemical quality as well as microbial decontamination of the sample. It has been generally observed that influence of optimum-dose range of irradiation on the physicochemical qualities was insignificant, which was proved in the organoleptic evaluations on the stored sample.