• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.510-518
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• 2003

Protective effects of natural components including genistein (4',5,7-trihydroxyisoflavone) from Glycine max MERRILL on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. Genistein $(10{\sim}100\;{\mu}m)$ suppressed photohemolysis in a concentration-dependent manner, and was more effective than the lipid peroxidation chain blocker, ${\alpha}$-tocopherol (Vit. E). Glycoside of genistein, genistin, the water-soluble antioxidant, L-ascorbate, and the iron chelator, myo-inositol hexaphosphoric acid dodecasodium salt (sodium phytate) did not exhibit protective effect against photohemolysis. L-Ascorbate and sodium phytate stimulated photohemolysis at high concentration $(500\;{\mu}m)$. ${\alpha}$-Carotene 3,3'-diol (lutein), a singlet oxygen $(^1O_2)$ quencher, exhibited pronounced protective effect, an indication that $^1O_2$ is important in photohemolysis sensitized by rose-bengal. Reactive oxygen scavenging activities $(OSC_{50})$ of natural antioxidants including genistein on reactive oxygen species (ROS) generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay were in the order of sodium phytate > L-ascorbate > ${\alpha}$-tocopherol > genistein > genistin. $OSC_{50}$ value of genistein, genistin, ${\alpha}$-tocopherol, L-ascorbate, and sodium phytate were 41.0, 109.0, 9.0, 5.2, and $0.56{\mu}m$ respectively. The order of free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity $(FSC_{50})$ was L-ascorbate > ${\alpha}$-tocopherol > genistein > genistin. These results indicate that genistein can function as an antioxidant in biological systems, particularly skin exposed to solar UV radiation by scavenging $^1O_2$ and other ROS, and to protect cellular membranes against ROS.

• Journal of Ginseng Research
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• v.17 no.3
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• pp.232-235
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• 1993

We investigated the effect of antioxidants (ascorbate, glutathione, and sodium azide), which efEectively inhibited the chlorophyll bleaching of Panax ginseng CA Meyer under the high light intensity, treated by folilar wiping on the early stage of photosynthesis and transpiration of ginseng in the 5000 $\mu$mol photon.$m^{-2}$.$s^{-1}$. Ascorbate and glutathione, endogenous antioxidant, completely recovered ginseng from the photoinhibition, but sodium azide, synthetic quencher, showed negative effect. We assumed that endogenous antioxidants could be available to the protection of the leaf-burning phenomenon of ginseng.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.73-80
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• 2014

Pretreatment of chinese cabbage leaves with $100{\mu}M$ sodium nitroprusside (SNP), a nitric oxide (NO) donor, effectively improved their tolerance to subsequent $2{\mu}M$ paraquat (PQ)-induced oxidative damage. The fresh weight, and chlorophyll and protein contents in primary leaves treated with PQ alone were noticeably reduced over 24 h light incubation. However, these leaf injury symptoms were significantly alleviated with $100{\mu}M$ SNP pretreatment for 3 h prior to PQ exposure. In additions, the increase of the contents of malondialdehyde (MDA) and $H_2O_2$ due to PQ exposure were significantly inhibited by SNP pretreatment. Together with the protective effects of SNP against PQ toxicity in leaves, the changes of ascorbate-glutathione cycle enzymes activities were examined. In the PQ alone treatment, the activities of APX, DHAR, and GR after 6 h incubation were rapidly reduced and showed 19%, 50% and 39% respectively, compared with those of the control. However, the decreases in these enzyme activities were significantly inhibited by SNP pretreatment. As a result, their activities were higher than those of PQ alone treatment by 5 times, 2 times, and 1.5 times, respectively, at 6 h incubation. Thereafter, these enzymes decrease their activities gradually showing high levels than those of PQ alone. Based on the above results, it can be assumed that the activation of ascorbate-glutathione cycle by SNP pretreatment in chinese cabbage leaves exposed to PQ can prevent $H_2O_2$ accumulation, thereby leading to protection against PQ-induced oxidative stress. Also, these results indicate that NO acts as an protectant against PQ stress in the leaves of chinese cabbage.

• Restorative Dentistry and Endodontics
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• v.38 no.1
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• pp.43-47
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• 2013

Objectives: The aim of this study was to determine an appropriate application duration of sodium ascorbate (SA) antioxidant gel in reducing microleakage of bonded composite restoration in intracoronally-bleached teeth. Materials and Methods: Eighty endodontically-treated human incisors were randomly divided into eight groups: control, no bleaching; IB and DB, immediate and delayed bonding after bleaching, respectively; S10m, S60m, S24h, S3d and S7d, bleaching + SA gel for 10 min, 60 min, 24 hr, 3 day and 7 day, respectively. For bleaching, a mixture of 30% hydrogen peroxide and sodium perborate was applied for 7 day. All access cavities were restored using One-Step adhesive (Bisco Inc.) and then Aelite LS Packable composite (Bisco Inc.). The bonded specimens were subjected to 500 thermal cycles, immersed in 1% methylene blue for 8 hr, and longitudinally sectioned. Microleakage was assessed with a 0 - 4 scoring system and analyzed using nonparametric statistical methods (${\alpha}$ = 0.05). Results: Group IB showed a significantly higher microleakage than the control group (p = 0.006) and group DB a statistically similar score to the control group (p > 0.999). Although groups S10m, S60m, and S24h exhibited significantly higher scores than group DB (p < 0.05), the microleakage in groups S3d and S7d was statistically similar to that in group DB (p = 0.771, p > 0.999). Conclusions: Application of SA gel for 3 day after nonvital bleaching was effective in reducing microleakage of composite restoration in intracoronally-bleached teeth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.2
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• pp.93-98
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• 1983

Apple sugaring and apple nectar gel were treated with coating agent, and then the rate of weight loss, browning reaction and fungi growth on the storage conditions of those were investigated. The results obtained were summarized as follows; The composition of sucrose, D-sorbitol, corn syrup, gelatin, arabia gum, citric acid, sodium citrate and sodium ascorbate as a nontoxic coating agent was desirable to repress weight loss browning reaction and fungi growth of apple sugaring and apple nectar gel. It was the most effective method that apple sugaring was treated with the coating agent and refrigerated with double packaging. The contraction by weight loss, browning reaction and fungi growth of apple nectar gel treated with the coating agent and freezed with double packaging were repressed.

• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.37-43
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• 2015

Objectives: Some antioxidants are believed to restore dentin bond strength after dental bleaching. This study was done to evaluate the influence of antioxidants on the bond strength of bleached bovine dentin. Materials and Methods: Thirty incisors were randomly assigned to 10 groups (two unbleached control and eight bleached groups:immediate bonding IB, 4 wk delayed bonding DB, 10% sodium ascorbate treated SA, 10% ${\alpha}$-tocopherol treated TP groups). Teeth in half of groups were subjected to thermal stress, whereas the remaining groups were not. Resin-dentin rods with a cross-sectional area of $2.25mm^2$ were obtained and microtensile bond strength was determined at a crosshead speed of 1 mm/min. Fifteen specimens were prepared for SEM to compare the surface characteristics of each group. The change in dentin bond strength from thermal stress and antioxidant treatment was evaluated using two-way analysis of variance (ANOVA) and Sheffe's post hoc test at a significance level of 95%. Results: The control group exhibited the highest bond strength values, whereas IB group showed the lowest value before and after thermocycling. The DB group recovered its bond strength similar to that of the control group. The SA and TP groups exhibited similar bond strength values with those of the control and DB groups before thermocycling. However, The TP group did not maintain bond strength with thermal stress, whereas the SA group did. Conclusions: Applying a 10% sodium ascorbate solution rather than 10% ${\alpha}$-tocopherol solution for 60 sec is recommended to maintain dentin bond strength when restoring non-vitally bleached teeth.

• BMB Reports
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• v.31 no.1
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• pp.70-76
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• 1998

The final step in ethylene biosynthesis is catalyzed by the enzyme 1-aminocyclopropane-1-carboxylate (ACC) oxidase. ACC oxidase was extracted from mung bean hypocotyls and its biochemical characteristics were determined. In vitro ACC oxidase activity required ascorbate and $Fe^{2+}$, and was enhanced by sodium bicarbonate. Maximum specific activity (approximately 20 nl ethylene $h^{-1}$ mg $protein^{-1}$) was obtained in an assay medium containing 100 mM MOPS (pH 7.5), $25\;{\mu}M$ $FeSO_4$, 6 mM sodium ascorbate, 1 mM ACC, 5 mM sodium bicarbonate and 10% glycerol. The apparent $K_m$ for ACC was $80{\pm}3\;{\mu}M$. Pretreating mung bean hypocotyls with ethylene increased in vitro ACC oxidase activity twofold. ACC oxidase activity was strongly inhibited by metal ions such as $Co^{2+}$, $Cu^{2+}$, $Zn^{2+}$, and $Mn^{2+}$, and by salicylic acid. Inactivation of ACC oxidase by salicylic acid could be overcome by increasing the $Fe^{2+}$ concentration of the assay medium. The possible mode of inhibition of ACC oxidase activity by salicylic acid is discussed.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.636-648
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• 2020

This study investigated the effects of the addition levels of white kimchi powder and acerola juice powder, as natural sources of sodium nitrite and sodium ascorbate, on the quality of cooked ground pork products. Freeze-dried white kimchi powder was prepared and used after fermentation for 2 wk. Six treatments were included: control (100 ppm sodium nitrite and 500 ppm sodium ascorbate), treatment 1 (0.2% white kimchi powder, 0.02 % starter culture, and 0.1% acerola juice powder), treatment 2 (0.2% white kimchi powder, 0.02% starter culture, and 0.2% acerola juice powder), treatment 3 (0.4% white kimchi powder, 0.04% starter culture, and 0.1% acerola juice powder), treatment 4 (0.4% white kimchi powder, 0.04% starter culture, and 0.2% acerola juice powder), and treatment 5 (0.4% celery powder, 0.04% starter culture, and 0.2% acerola juice powder). The pH values were decreased (p<0.05) because of lower pH of acerola juice powder, resulting in lower cooking yields (p<0.05) in these treatments. CIE L* and CIE a* values of indirectly cured meat products were not different (p>0.05) from the sodium nitrite-added control. However, indirectly cured meat products showed lower (p<0.05) residual nitrite contents, but higher (p<0.05) nitrosyl hemochrome contents and cure efficiency than the control. Treatments 2 and 4 had higher (p<0.05) total pigment contents and lipid oxidation than the control. This study indicates that white kimchi powder coupled with acerola juice powder has substantial potential to substitute synthetic nitrite to naturally cured meat products, which could be favored by consumers seeking clean label products.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.268-268
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• 1996

No Abstract, See Full Text

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.384-388
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• 2002

Gamma irradiation was used to reduce the N-nitrosamines in emulsion-type cooked pork sausage during storage at 4$^{\circ}C$. The sausage without ascorbate to maximize the N-nitrosamine formation and the sausage with 200 ppm sodium ascorbate were prepared, respectively. The sausages were aerobically or vacuum packaged and irradiated at 0, 5, 10 and 20 kGy. A statistically significant difference was not shown in N-nitrosodimethylamine (NDMA) and N-nitrosopyrrelidine (NPYR) levels in the sausage prepared with sodium ascorbate at 0 week, while the NDMA and NPYR reduction was observed after 4 weeks storage. The NDMA level in the sausage without sodium ascorbate and irradiated at 10 kGy or above reduced in aerobic packaging, while a dose of 20 key was needed in vacuum packaging. The N-nitroscpyrrolidine reduction was shown at 20 and 30 kGy-irradiation. The results indicated that gamma irradiation was effective to reduce N-nitrosamines level in sausage during storage.