• Korean Journal of Food Science and Technology
• /
• v.35 no.6
• /
• pp.1129-1134
• /
• 2003

Changran jeotkal, a Korean traditional fermented seafood, was prepared as a pilot scale using a commercial method and irradiated at 0, 2.5, 5.0 and 10 kGy by gamma ray to investigate possibilities for further industrial application. To see the effectiveness and rapid industrialization, hot pepper powder was irradiated at 10 kGy and manufactured the changran jeotkal (HP-10 kGy) as same method since the hot pepper powder was approved legally for gamma irradiation in Korea. The content of volatile basic nitrogen and amino nitrogen was significantly reduced by gamma irradiation in all storage periods. Amino nitrogen contents of 0, 2.5, 5.0, 10 kGy and HP-10 kGy were 98.9, 98.5, 92.4, 88.0 and 93.1mg%, respectively after 12 week of storage at $10^{\circ}C$. In total, 8 kinds of biogenic amines were found from the samples, and the contents in the gamma irradiated changran Jeotkal were lower than those of the control during storage. The sample of HP-10 kGy showed similar physicochemical characteristics to the sample irradiated as $2.5{\sim}5.0\;kGy$. Results indicated that gamma irradiation of fermented seafood products such as seasoned changran jeotkal improved quality stability, thus, we recommend gamma irradiation for industrial application.

• Research in Plant Disease
• /
• v.20 no.2
• /
• pp.79-86
• /
• 2014

In order to seek more eco-friend, economic and safer quarantine method than current methyl bromide fumigation, the convergent treatment with 200 Gy of gamma irradiation and several chemicals such as nano-siver particles (NSS), sodium dichloroisocyanurate (NaDCC) was tried on the cuttings of lily in the packing of catonnage box for export. With 6 independent experiments of gamma irradiation on the three lily cultivars, cvs. Siberia, Le reve and Sorbonne, incidence and severity of lily leaf blight was investigated on leaves and petals at 8-d after infection. 200 Gy of gamma irradiation decreased at 13-25% of severity on the leaf of Sorbonne, but it increased at 2-5% of severity on the leaf of Siberia and Le reve. Chemical substitutes such as NSS and NaDCC were not effective to control of lily blight on cuttings. By 200 Gy of gamma irradiation treatment, chlorophyll contents were statistically significantly decreased at 12-d after irradiation and the longevities vaselife of fully open flower of Siberia and Sorbonne were increased at 0.4 to 1.2 days. In addition, the relative fresh weights of the gamma irradiated cuttings were severely dried compared to the non-irradiated control. On the other hands, the symptoms of phyto-toxicity of high dose gamma irradiation at 1 or 2 kGy on cv. Siberia were to be blight at the tip of bloom, bent necks of flower, and delayed the process of flowering.

• Korean Journal of Microbiology
• /
• v.6 no.2
• /
• pp.41-53
• /
• 1968

Studies on the carbohydrate metabolism of yeast as influenced by gamma-irradiation from cobalt-60 have been carried, then the mechanisms of radiation effect on respiration and fermentation were discussed under considerations of permeable changes of irradiated cell membrane. The cells of baker's yeast (Saccharomyces cerevisiae) which had been gamma-irradiated of 240 k.r. doses for an hour, then were put into aerobic oxidation and anaerobic fermentation without substrate. Total and fractionated carbohydrates of irradiated yeast cells were determined by calorimetric method with anthrone and orcinol reagents, the amounts of total carbohydrate, trehalose, RNA-ribose, PCA-soluble glycogen, alkali-soluble glycogen, acetic acid-soluble glycogen, mannan and glucan were determined according to the course of aerobic oxidation and anaerobic fermentation. It is found that the carbohydrates of irradiated cells leak out and amount of the losses teaches eleven times more than that of control, the volume of losses are seems to be replaced by water, it can be suggested the damage of gamma-irradiation occurs in the site of passive transport of cell membrane. The endogeneous aerobic respiration of irradiated cells are increased much more than control, the synthesis of reserve glycogen, glucan and RNA-ribose promoted much more than control. The anaerobic fermentation of irradiated cells are also increased than that of control, but the breakdown of carbohydrate is less than endogeneous respiration of irradiated cells. The synthetic rate is also less than that of aerobic oxidation. In irradiated yeast cells, trehalose is revealed to be primary substrate for endogeneous carbohydrate metabolism, so it is proved that the enzymic patterns are not changed but the activities of enzymes relating endogeneous respiration and autofermentation is activated. It is to be considerable to distiguish endogeneous respiration and autofermentation from exogeneous respiration and fermentation on irradiation, for membrane permeability changes and loses out carbohydrate by ionizing radiation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.3
• /
• pp.505-509
• /
• 2001

This study was carried out to evaluate the application of food irradiation technology as a method for reducing milk allergies. Bovine $\alpha$-casein, $\beta$-casein, $textsc{k}$-casein, $\alpha$-lactalbumin(ALA), $\beta$-lactoglobulin (BLG) and serum albumin (BSA) were used as model allergens of milk proteins and the proten solution (2.0 mg/mL) with 0.01 M phosphate buffered saline (pH 7.4) was irradiated at 3, 5 and 10 kGy. Using milk-hypersensitive patients IgE (MHP-IgE), the changes of binding ability to irradiated proteins were observed by competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). Affinity of MHP-IgE to milk proteins was higher in ALA and BLG than that of other proteins. Standard curve to each non-irradiated protein could be made with MHP-IgE for quantifying milk allergens. Binding abilities of MHP-IgE to the irradiated proteins, however, decreased with different slopes of the standard curves. Sensitivity of gamma irradiation was higher in ALA and BLG than of other proteins. These results indicated that irradiation technology can be used to reduce the milk hypersensitivity.

• Journal of the Korean Chemical Society
• /
• v.11 no.2
• /
• pp.77-80
• /
• 1967

Radiolysis of polyacrylonitrile(PAN) has been studied. Parameters for crosslinking and scission induced by gamma-ray irradiation were obtained by means of sol-gel partitioning method. G-value of crosslinking in PAN ($\bar{M}n=6{\times}10^5$) was 0.038 and the gel dose 21.6 Mrad. The effects of irradiation on the thermal degradation rate in PAN was also studied. No appreciable changes in thermal degradation rate observed up to 81.8 Mrad of irradiation dose.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.12
• /
• pp.2066-2075
• /
• 2016

In this study, an enhanced lipid-producing mutant strain of the microalga Chlamydomonas reinhardtii was developed by gamma irradiation. To induce the mutation, C. reinhardtii was gamma irradiated at a dose of 400 Gy. After irradiation, the surviving cells were stained with Nile red. The mutant (Cr-4013) accumulating 20% more lipid than the wild type was selected. Thin-layer chromatography revealed the triglyceride and free fatty acid contents to be markedly increased in Cr-4013. The major fatty acids identified were palmitic acid, oleic acid, linoleic acid, and linolenic acid. Random amplified polymeric DNA analysis showed partial genetic modifications in Cr-4013. To ascertain the changes of protein expression in the mutant strain, two-dimensional electrophoresis was conducted. These results showed that gamma radiation could be used for the development of efficient microalgal strains for lipid production.

• Korean Journal of Veterinary Research
• /
• v.41 no.2
• /
• pp.219-225
• /
• 2001

The gamma-radiation sensitivity of three kinds of pathogenic bacteria to fish was investigated. $D_{10}$ values (irradiation dose required to inactivate 90% of the population) of Edwardsiella tarda, Vibrio anguillarum and Streptococcus faecalis were 0.08, 0.10 and 0.44 kGy, respectively. The inactivation factors were 4.50 - 24.30 and 6.75 - 36.45 at radiation doses of 2 and 3 kGy. Raw moist pellets were inoculated with Edwardsiella tarda, Vibrio anguillarum or Streptococcus faecalis. Inoculated feed samples were packaged in air and irradiated at 5 kGy. This dose was effective in controlling the inoculated and general bacteria in fish feed. We consider gamma-radiation to be an effective method to sterilize pathogenic bacteria in fish feed.

• Food Science and Biotechnology
• /
• v.14 no.3
• /
• pp.355-357
• /
• 2005

This study evaluated the binding abilities of rabbit anti-ovalbumin (OVA) immunoglobulin G (IgG) and egg-allergic patient IgE on gamma-irradiated OVA during proteolysis using pepsin and trypsin. The concentrations of both the intact and the irradiated OVAs decreased during proteolysis when detected with IgG However, when detected by patient IgE the concentration of the intact OVA decreased up to 30 min after the trypsin treatment and increased thereafter. Irradiated OVA detected by patient IgE showed a lower initial concentration (0.16%) than that of the intact OVA, and this reduced concentration was maintained stably. The results indicate that irradiation, rather than enzymatic treatment, could reduce the binding of the irradiated and enzyme-treated OVA. Therefore, gamma irradiation has potential as an effective method to reduce OVA-induced allergy and may enhance the safety of egg-allergic individuals.

• Journal of Radiation Industry
• /
• v.5 no.1
• /
• pp.35-39
• /
• 2011

This study was investigated the effect of tumor cell cytotoxicity of gamma irradiated Chaga mushroom extract (CME). CME was prepared by hot water extraction at $70^{\circ}C$ for 4 hours and lyophilized. $Ten\;mg\;ml^{-1}$ of lyophilized CME powder was dissolved with deionized water and then irradiated at the doses of 10, 50, 100, and 150kGy by cobalt 60 gamma irradiator. The gamma-irradiated and non-irradiated CME were treated into the cancer cell, including human stomach cancer and human colon cancer. Cytotoxicity against the cancer cell was increased in gamma-irradiated CME and antioxidant activity was also increased in gamma-irradiated CME, as irradiation dose increased. Therefore, it was considered that gamma irradiation was effective method for improvement of the cancer cell cytotoxicity and antioxidant activity of Chaga mushroom extract.

• Korean Journal of Food Science and Technology
• /
• v.17 no.4
• /
• pp.311-318
• /
• 1985

This review was intended to develop the sterilization method of spices by gamma irradiation and the results are summarized as follows. Microbial load of spices was different according to the kind of spices and the number was ranged from $10^{2}$-$10^{5}/g$ to $10^{7}$-$10^{8}/g$, gamma irradiation up to 4-10 kGy could decreased or sterilized to the microorganism of spices. In physicochemical properties of spices such as chemical components,essential oil and flavor, irradiated group with optimum dose was almost similar to the nonirradiated one, while fumigant treated group was remarkably deteriorated in the properties of spices compared with control, and free radicals produced by irradiation was disappeared during a few days storage. Irradiated spices should be an aptitude for good quality the storeability of processing food. Optimum dose irradiation below less than that proposed by FAO/IAEA/WHO Joint Committee and FDA was remarkably effect on the sterilization of spices and superior in wholesomeness and economic feasibiity compared with traditional methods. Irradiation might be an alternative to traditional sterilization methods of spices by fumigants such as ethylene oxide and ethylene dibromide because their treatments have been banned in U.S.A and other countries since 1982.