• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.170-173
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• 2002

Electron spin resonance (ESR) spectroscopy was used to detect free radicals in irradiated wheat flour and glutinous rice flour. They were irradiated with doses of 0, 0.1, 0.5, 1 and 2 kGy at room temperature using a Co-60 irradiator. Free radicals detected for irradiated wheat flour and glutinous rice flour were higher than those of unirradiated ones. Since concentration of free radicals linearly increased with applied doses $(0.1{\sim}2\;kGy)$, highly positive correlation coefficients $(R^2=0.9995{\sim}0.9998)$ were obtained between irradiation doses and free radical concentrations right after irradiation. Although concentration of free radicals slowly decreased with storage time, the characteristic ESR signals of free radical in irradiated samples were observed even after 4 weeks of storage at room temperature.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.57-61
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• 2002

Electron spin resonance (ESR) spectroscopy was used to investigate the effect of irradiation dose and storage time on the free radical concentrations in gamma-irradiated dried seasoning powder. Seasoning powders of dried squid flavor, shrimp flavors, kimchi flavor, spicy beef soup flavor and soy sauce flavor were irradiated with doses of 0, 1, 3, 5, 7 and 9 kGy at room temperature using a Co-60 irradiator. Characteristic signals of free radicals were observed in all the irradiated samples of this experimental while these signals were not detected in non-irradiated samples. Since the free radical concentrations linearly increased with the applied doses (1~9 kGy), highly positive correlation coefficients ($R^2$ = 0.9285~0.9965) were obtained between irradiation doses and free radical concentrations during all the storage times. Free radical concentrations of the irradiated flavored seasoning powder did not change even at 16 weeks of storage at room temperature, while those of dried squid, shrimp and spicy beef soup flavors decreased until 2 weeks of storage after irradiation with 5 kGy or over, and these of soy cause flavors slowly decreased until 8 weeks of storage after irradiation with 3 kGy or over. Although the free radical concentrations decreased with storage times, the characteristic signals of the irradiated seasoning powders of dried squid, shrimp, spicy beef and soy sauce flavors were observed even after 16 weeks of storage at room temperature.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.345-348
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• 2004

Dried cabbage, spinach, carrot, mugwort and yam were irradiated at 1, 5 and 10 kGy using a $^{60}Co$ irradiator at room temperature. Effects of irradiation dose and storage time on irradiated dried vegetables were investigated through electron spin resonance (ESR) spectroscopy. Strong positive correlation coefficients ($R^{2}=0.9698-0.9915$) were obtained between irradiation dose and corresponding ESR signal intensity. ESR signal of mugwort was most stable at 9 weeks storage, followed by carrot, yam, and spinach, whereas that ESR signal of cabbage was not distinguishable.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.317-323
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• 2004

Photostimulated Luminescence (PSL), Electron Spin Resonance (ESR) and Thermoluminescence (TL) analysis were conducted to detect irradiation treatment of imported whole and ground spices. The screening by PSL detected no irradiation treatment, except un the ground thyme and bay leaves which exhibited photon counts in the intermediate level. Irradiation of the two spices was detected after irradiating them at 1.0, 3.0, 5.0 and 10.0 kGy, and then subjecting them to PSL analysis, which resulted in the significantly low photons of non-irradiated spices compared to that at 1.0 kGy, indicating that the photon counts varied depending on the amount of inorganic mineral debris in the spices. To confirm a successful detection by using PSL, ESR and TL methods, some spices were selected, irradiated at 5.0 and 10.0 kGy, and subjected to the detection methods. PSL identified the irradiated spices except the cassia, which showed very weak PSL sensitivity, but was identified by ESR analysis. Also, the ESR and TL exhibited the typical signals induced by irradiation treatment and were able to successfully detect all of the irradiated spices. In addition, we found a positive correlation between the intensity of ESR and TL signals and irradiation doses.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.184.2-184.2
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• 2013

대기압 플라즈마와 생체용액과의 상호작용은 Bio-medical 분야에서 주목 받고 있다. 대기압 플라즈마는 전자온도가 고온 플라즈마 보다 상대적으로 낮기 때문에 생체에 적용하기가 적합하다. 따라서 플라즈마가 세포에 미치는 영향을 관측하기 위해서 대기압 플라즈마를 이용하여 생체용액과의 반응을 살펴보고자 한다. Ar gas를 이용하여 플라즈마를 발생시켜 생체용액 표면을 처리하고 OES (Optical Emission Spectroscopy)을 이용해 방출 선을 조사했다. Ar 기체를 이용한 대기압 플라즈마를 사용하여 다른종류의 용액내의 OH Radical Density를 측정하였다. 용액으로는 DI (deionized) water 와 PBS (1x phosphate buffered saline)를 사용하였다. Ar gas를 200 sccm ($cm^3/min$) 으로 흐르게 하였을 때, DI water의 OH Radical Density 는 $4.33{\times}10^{16}cm^{-3}$ 으로 측정되었으며, 자외선 흡수분광법으로 측정한 완충용액인 PBS의 OH Radical Density 측정값은 $1.87{\times}10^{16}cm^{-3}$ 이다. 이런 특성을 기반으로, PBS 용액내의 H460 (Lung Cancer Cell) 와 L132 (Lung Normal Cell)을 깊이와 시간에 따라 대기압 플라즈마로 처리하여 cell의 변화를 보았다. 실험 각각의 조건은 깊이를 2 mm, 4 mm, 6 mm이며 시간은 10 sec, 30 sec, 60 sec 로 설정하였다. 표면으로부터의 깊이가 2 mm, 4 mm, 6 mm 일때 의 OH Radical Density는 각각 $1.87{\times}10^{16}cm^{-3}$, $0.5{\times}10^{16}cm^{-3}$, 0으로써 용액이 깊어질수록 OH Radical Density가 감소함을 볼 수 있다. OH radical density가 높은 2 mm 에서, 처리한 시간이 길어질수록 Cell 은 영향을 많이 받음을 관찰 할 수 있었다. H460 이 L132 보다 플라즈마에 영향을 많이 받음을 확인하였다. 특성변화를 알아보기 위하여 raman spectroscopy, flow cytometry, electron spin resonance로 측정한다.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.126-135
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• 2006

Phlorotannins which is oligomeric polyphenol of phloroglucinol unit were isolated from solvent fractions of methanolic extract of the brown alga, Ecklonia cava (EC). The inhibitory effects of phlorotannins from EC solvent fractions on oxidative stress were examined in human dermal fibroblasts (HDFs) related to wrinkle formation. Among the solvent fractions, phlorotannins from ethyl acetate fraction exerted the highest scavenging effect on DPPH radical, hydroxyl radical and alkyl radical analyzed by electron spin resonance (ESR) spectroscopy. The levels of intracellular reactive oxygen species (ROS) and lipid peroxidation were measured using 2',7'-dichlorofluorescin diacetate (DCFH-DA) and diphenyl-1-pyrenylphosphine (DPPP), respectively. Their levels were significantly decreased in the presence of phlorotannins from ethyl acetate fraction, compared with other fractions obtained from EC extract (P < 0.01). Furthermore, intracellular glutathione (GSH) level was significantly increased in a time dependent manner by the phlorotannins. Therefore, these results suggest that phlorotannins from EC extract could have a therapeutic potential for prevention and treatment of several diseases such as wrinkle formation related to oxidative stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.854-857
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• 2001

Electron spin resonance (ESR) spectroscopy was used to detect free radicals in irradiated dried vegetables. Dried carrot, mushroom and green onion were irradiated with doses of 0, 1, 3, 5 and 7 kGy at room temperature using a Co-60 irradiator. Free radicals were detected in irradiated dried carrot, green onion and mushroom, while those were not detected in non-irradiated samples. Since concentration of free radicals linearly increased with applied doses (1~7 kGy), highly positive correlation coefficients ($R^2$=0.9747~0.9919) were obtained between irradiation doses and free radical concentrations right after irradiation. Although concentration of free radicals slowly decreased with storage time, the characteristic ESR signals of free radicals slowly decreased with storage time, the characteristic ESR signals of free radical in irradiated samples were observed even after 3 months of storage at room temperature.

• Journal of Radiation Industry
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• v.6 no.2
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• pp.119-123
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• 2012

The detection properties of gamma-irradiated (0~10 kGy) dried seaweed, dried shrimp, and seasoned dried filefish were investigated by photo-stimulated luminescence (PSL) and electron spin resonance (ESR). PSL could be used as a detection method on irradiated dried seaweed and dried shrimp as they showed photon counts greater than 5,000 counts/60 s (positive) in the irradiated samples with doses above l kGy. However, PSL could not be applied to detect irradiated seasoned dried filefish, because gamma-irradiated sample at 10 kGy even yielded photon counts less than 700 counts/60 s (negative). The ESR spectroscopy for only dried shrimp revealed specific signals derived from free radicals captured in the shell of shrimp. As a result, it is considered that PSL or ESR methods for detection of gamma-irradiated dried shrimp and only PSL can be used to detect gamma-irradiated seaweed. Furthermore, it is considered that hydrocarbon analysis of seasoned dried filefish containing fat by GC/MS and Thermo Luminance (TL) analysis of dried seaweed should be studied for detection of irradiation.

• Biomedical Science Letters
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• v.25 no.3
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• pp.227-236
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• 2019

In this study, the anti-oxidant, anti-inflammatory, and anti-obesity activities of an ethanol extracts of Ulmus divididiana var. japonica (UDE) were investigated in vitro and in vivo. UDE anti-oxidant activity was evaluated with an Electron Spin Resonance (ESR) spectrometer, which measured 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity. Cell viabilities were estimated using 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. LPS-stimulated BV-2 microglia were used to study the production of nitric oxide (NO). Cells stimulated with LPS produce more NO than normal control cells. However, cells treated with the UDE decreased this production in a concentration dependent manner (100, 250, 500, $1,000{\mu}g/mL$). Also, we investigated the anti-obese activity of UDE in SD rats. The SD rats were randomly divided into five groups: 10% low fat diet (N), 45% high fat diet (H), 45% high fat diet + garcinia extracts 200 mg/kg/day (HG200), high fat diet + UDE 200 mg/kg/day (HU200), high fat diet + UDE 400 mg/kg/day (HU400). UDE was found to lower whole body and abdominal and epididymal adipose tissue weights and lowered plasma levels of triglyceride (TG), compared to those in H group. Histological analyses of the liver and fat tissues of rat treated with UDE revealed significantly decreased number of lipid droplets and decreased size of adipocytes compared to the H group. These results suggest that UDE might be used to develop potent anti-oxidant, anti-inflammatory, and anti-obesity agents, and may be useful as ingredients for related new functional raw materials.

• Journal of Plant Biotechnology
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• v.49 no.2
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• pp.150-154
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• 2022

This study examined the antioxidant activity of ethanol extract and fraction from Castanea crenata inner shell in vitro. Antioxidant activity was evaluated through total polyphenol and flavonoid contents and DPPH radical scavenging ability using electron spin resonance (ESR). The total polyphenol contents of the 70% ethanol extract and ethyl acetate fraction were 39.76 mg GAE/g and 323.92 mg GAE/g (p < 0.05). The total polyphenol contents of the ethyl acetate fraction were higher than other fractions. Furthermore, the total flavonoid contents of ethyl acetate were higher than other fractions at 13.12 mg QE/g (p < 0.05). In DPPH radical scavenging ability measurement, the RC₅₀ value of ethyl acetate was lower than ascorbic acid at 2.27 ㎍/mL (p < 0.05). In conclusion, this result showed that the ethyl acetate fraction of Castanea crenata inner shell 70% ethanol extract has high antioxidant activity.