• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.119-129
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• 1992

Black soybeans were gamma-irradiated at dost levels of 0, 2., 5, 10 and 20 kGy, and stored at room temperature for the experiments associated with cooking quality. The degree of cooking of soybeans in boiling water at 98-10$0^{\circ}C$ has been determined by measuring the maximum cutting force of cotyledon. The cutting force to reach a complete cooking was about 120~130g/g. Irradiation at 2.5~20kGy caused the reduction of cooking time in black soybeans by 30~60% compared to the nonirradiated control, and the cooking rate constant of the irradiated samples was higher than that fo the nonirradiated control sample. These results were similarly found in the stored samples for one year at room temperature after irradiation. Color characteristics of cooked samples showed no significant difference between the nonirradiated control and 5 kGy-irradiated sample. After complete cooking of black soybeans, there were not significant in the organoleptic qualities between the nonirradiated and irradiated samples.

• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.101-117
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• 1992

Effects of gamma irradiation(2.5∼20kGy) on water absorption property was studied for a local variety of black soybeans. In water absorption patterns of black soybeans, the time to reach a fixed moisture content was reduced depending on the increment of water soaking temperature and irradiation dose. Irradiation at 2.5∼10kGy resulted in the reduction of soaking time of black soybeans by about 1∼3 hours and the increase of hydration capacity by 10∼20%, respectively, compared to the nonirradiated control black soybean. The water uptake rate constant of the irradiated black soybean difinitely increased with the increase of dose levels and water soaking temperature. The activation energy for water absorption and z-value were lower in the irradiated black soybeans than in the nonirradiated control black soybean. The efficacy of water absorption property in the irradiated black soybeans was also recognized after one year of storage at room temperature.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.558-565
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• 1996

Some physicochemical properties of gamma-irradiated soybeans (0-20 kCy) were investigated. Proximate components, fatty acid compositions and minerals of the soybeans irradiated at 2.5 - 20 kGy shrived no difference from the nonirradiated control. Irradiation doses above 10 kGy and long term storage caused decrease in extractable phenols and phytate content, whereas increases in acid value and organic acid content. The total amino acids content of the soybeans irradiated up to 10 kGy was not changed as compared with the nonirradiated control. Sulfur-containing amino acids, however, were changed by 10 and 20 kGy irradiaton. Gamma irradiation and long term storage caused minor changes in the color attributes of soybeans. Hunter's 'L' (lightness) and 'b' (yellowness) values were decreased whereas 'a' (redness) value was increased with increasing dose levels and the elapse of the storage period.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.138-146
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• 2007

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades. Harmful contaminants naturally occurred from foods which contain high levels of unsaturated fatty acids that are easily oxidized can affect the human anti-oxidation system through the generation of free radicals. Moreover, previous studies proved that ${\gamma}$-irradiation may cause production of free radicals in food. We investigated the effect of ${\gamma}$-irradiated soybeans in relation to oxidative stress in mice. Oxidative index of mice was evaluated by TBARS, DNA fragmentation in various organs such as blood lymphocytes, liver and kidney. Forty male ICR mice were equally divided into 4 groups and fed control diet or ${\gamma}$-irradiated diet containing 50% soybeans (5, 10, and 20 kGy, respectively) for 8 weeks. Peroxide values of the irradiated diets were higher than that of the non-irradiated one and increased according to the storage period. There was no significant difference in weight gain as well as in TBARS value in plasma and kidney of all groups. Liver TBARS value of the group fed with irradiated diet at 20 kGy increased significantly compared with the control group (p < 0.05). DNA oxidative damage as measured by alkaline comet assay showed that % tail DNA in the blood lymphocytes of 5 kGy and 10 kGy groups increased significantly over the control group (p < 0.05). Also, tail moments of 5 kGy and 10 kGy groups were higher than that of the control group. Ultrastructural examination shows myeline figures and swollen mitochondria in parietal and intestinal epithelial cells of the group fed with irradiated diet. Therefore, considering unsaturated fatty acid content, consumption of soybeans ${\gamma}$-irradiated with over 20 kGy or repeatedly may decrease the body's antioxidant mechanism.

• Journal of Radiation Industry
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• v.6 no.4
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• pp.305-310
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• 2012

This study examined radiation detection properties of imported perilla seeds, almonds, and soybeans. Food samples were irradiated at doses of 0.5, 1, 2, and 4 kGy and analyzed by photo-stimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR). The results of PSL showed that photon counts of irradiated perilla seeds and soybeans were $32,959counts{\cdot}60sec^{-1}$ and $7,234counts{\cdot}60sec^{-1}$, respectively, at an irradiation dose of 0.5 kGy, and the photon count of irradiated almonds was $5,581counts{\cdot}60sec^{-1}$ at an irradiation dose of 1 kGy. The results of TL showed that this technique is useful for detecting irradiated samples; the TL ratios ($TL_1/TL_2$) measured for the food samples at an irradiation dose of 0.5 kGy were 0.2301 for perilla seeds, 0.4595 for almonds, and 0.4827 for soy beans. Lastly, results of ESR spectroscopy for only soybeans revealed specific signals derived from free radicals captured in the cellulose. In conclusion, PSL, TL, and ESR methods can be used for the detection of gamma-irradiated soybean samples, whereas gamma-irradiated perilla seeds and almonds can be confirmed by a serial detection with a TL method after PSL.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.252-257
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• 2017

In this study, the physicochemical properties of irradiated (gamma-ray and electron-beam) soybeans with different processing (dry and powder) and origins (Korea, China, and USA) were investigated and compared. The results of photostimulated luminescence (PSL) screening indicated that all non-irradiated soybeans showed photon counts (PCs) ${\leq}700$, while all irradiated soybeans showed positive values-gamma-ray 5,815-39,591 count/min; electron beam 5,791-60,055 count/min. The results of thermoluminescence (TL) analysis of all irradiated soybeans indicated that the $TL_1$ glow curves exhibited maximum peaks at 150-250. TL ratio of irradiated samples was ${\geq}0.1$; therefore, the clear identification of irradiated samples was guaranteed by analysis of the $TL_1$ curve shape and TL ratios. The results of electron spin resonance (ESR) signal of 3 irradiated and dried soybeans showed two side peaks mutually spaced at 6.0 mT (cellulose radical). Non-specific signal was detected for all irradiated soybean powders; hence, ESR analysis could not be performed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.796-803
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• 1996

Gamma irradiation was applied to soybean(Glycine max.), Hwangkeum, at dose levels of 0, 5, 10 and 20 kGy to improve the physical properties of soybeans. The time to reach a fixed moisture content was reduced depending on the increment of soaking temperatures and applied irradiation dose levels. Irradiation at 5~20 kGy resulted in reduction in soaking time of the soybeans by about 3~6 hrs at soaking temperature of $20^{\circ}C.$ The degree of cooking of soybeans in boiling water was determined by measuring the maximum cutting force of cotyledon. The cutting force to reach complete cooking was about 145g/g. Irradiation at 5~20 kGy resulted in a reduction of cooking time of soybeans by 55~75% as compared to the nonirradiated soybean. In electron microscopic observation of seed coat inner, the parenchyma of nonirradiated soybean showed tight fibrillar structure, whereas that of irradiated soybeans showed loosened and deformed structure. The microstructure of compressed cells and cotyledon epidermis was also deformed by gamma irradiation. In subcellular structure of cotyledon, the roundness of protein body was deformed and changed to spike shape at 20 kGy. Also, the size of lipid body decreased as the irradiation dose levels increased.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.18-23
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• 2002

The detection characteristics of gamma-irradiated $(0{\sim}4\;kGy)$ soybeans produced in Korea and China were investigated by thermoluminescene (TL), electron spin resonance (ESR), and DNA comet assay. The TL glow curves were shown at around $200^{\circ}C$ for irradiated soybeans, while that at $280^{\circ}C$ for the non-irradiated one. The normalization with a re-irradiation step at 1 kGy could verify the above detection results. The Korean soybean showed higher glow curves than Chinese did. The ESR spectroscopy for husks of irradiated soybeans revealed specific signals (g = 2.02374, 1.98715) derived from cellulose radical, which intensities were proportional to irradiation does, with the higher peaks in Chinese sample than Korean one. The DNA comet for the non-irradiated sample showed no or little tails, while those for irradiated samples above 0.5 kGy were remarkably changed in their length, size, and concentration, thus resulting in distinguishing non-irradiated from irradiated samples. As a result, TL, ESR, and DNA comet determinations were found suitable for the detection of irradiated soybean at 0.5 kGy or more, and negligible differences were observed between Korean and Chinese origins in their detection characteristics.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.4
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• pp.534-541
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• 2009

The aim of this study was to evaluate the effects of gamma irradiation (${\gamma}$-irradiation) at doses of 15, 30 and 45 kGy on chemical composition, anti-nutritional factors, ruminal dry matter (DM) and crude protein (CP) degradibility, in vitro CP digestibility and to monitor the fate of true proteins of full-fat soybean (SB) in the rumen. Nylon bags of untreated or ${\gamma}$-irradiated SB were suspended in the rumens of three ruminally-fistulated bulls for up to 48 h and resulting data were fitted to a nonlinear degradation model to calculate degradation parameters of DM and CP. Proteins of untreated and treated SB bag residues were fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Digestibility of rumen undegraded CP was estimated using the three-step in vitro procedure. The chemical composition of raw and irradiated soybeans was similar. Results showed that phytic acid in ${\gamma}$-irradiated SB at dose of 30 kGy was eliminated completely. The trypsin inhibitor activity of 15, 30 and 45 kGy ${\gamma}$-irradiated SB was decreased (p<0.01) by 18.4, 55.5 and 63.5%, respectively. From in sacco results, ${\gamma}$-irradiation decreased (p<0.05) the washout fractions of DM and CP at doses of 30 and 45 kGy, but increased (p<0.05) the potentially degradable fractions. Gamma irradiation at doses of 15, 30 and 45 kGy decreased (p<0.05) effective degradability of CP at a rumen outflow rate of 0.05 $h^{-1}$ by 4.4, 14.4 and 26.5%, respectively. On the contrary, digestibility of ruminally undegraded CP of irradiated SB at doses of 30 and 45 kGy was improved (p<0.05) by 12 and 28%, respectively. Electrophoretic analysis of untreated soybean proteins incubated in the rumen revealed that ${\beta}$-conglycinin subunits had disappeared at 2 h of incubation time, whereas the subunits of glycinin were more resistant to degradation until 16 h of incubation. From the SDS-PAGE patterns, acidic subunits of 15, 30 and 45 kGy ${\gamma}$-irradiated SB disappeared after 8, 8 and 16 h of incubation, respectively, while the basic subunits of glycinin were not degraded completely until 24, 48 and 48 h of incubation, respectively. It was concluded that ${\gamma}$-irradiated soybean proteins at doses higher than 15 kGy could be effectively protected from ruminal degradation.

• Journal of the East Asian Society of Dietary Life
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• v.8 no.4
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• pp.412-421
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• 1998

Physicochemical and microbiological properties of red beans, soybeans, barleys, and corns irradiated by gamma-ray at 1.2 kGy, 10.1 kGy, or 30.5 kGy were investigated. Moisture content and crude lipid content of the irradiated cereals showed no significant difference from the nonirradiated group. TBA values of corns irradiated at 30.5 kGy increased. Gamma irradiation reduced the numbers of mesophilic and psychrotrophic bacteria in the cereals. Yeasts and molds were reduced below detection levels even at 1.2 kGy dose-irradiation. There was no significant difference in reducing sugars between the irradiated cereals and the nonirradiated ones except corns. Stachyose, raffinose, and sucrose of soy beans and sucrose of barleys increased by 30.5 kGy dose-irradiation. Loss of riboflavin content of the irradiated samples was not observed except red beans irradiated at 30.5 kGy. In Hunter's color, b value of the red bean powder increased but L value of the soybean powder decreased by the Irradiation. L, a, and b values of the barley powder slightly increased under 30.5 kGy dose-irradiation and b value of the corn powder decreased under 10.1 or 30.5 kGy-dose irradiation.