• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.187-191
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• 2012

PURPOSE. The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores. MATERIALS AND METHODS. Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at ${\times}20$ magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM. RESULTS. Means of microtensile bond strength values (MPa) and standard deviations in the groups were as follows: G1: $9.70{\pm}0.81$; G2: $12.62{\pm}1.80$; G3: $16.60{\pm}1.93$; and G4: $21.24{\pm}1.95$. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode. CONCLUSION. Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol.

• Journal of Nutrition and Health
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• v.21 no.5
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• pp.295-304
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• 1988

To study effect of dietary polyunsaturated fatty acid and $\omega$-tocopherol content on lipid peroxidation in rat liver, rats were fed for 3, 6 and 9 weeks with normal tocopherol diet added 40mg of DL-$\alpha$-tocopherol/kg of diet (PF group), high tocopherol eit 200mg of DL-$\alpha$-tocopherol/kg of diet(PFE group), low tocopherol diet without addition of DL-$\alpha$-tocopherol to diet(PFO group), and control diet added 40mg of DL-$\alpha$-tocopherol/kg of diet(control group). Each diet group supplied 45% of total calorie from corn oil except control group which supplied 12% of total calorie from corn oil. After each feeding period, lipid peroxide and tocopherol contents were measured in the liver as well as activities of glutathione peroxidase and superoxide dismutase. PF group had almost the same contents of liver peroxide, tocopherol contents and activities of glutathione peroxidease and superoxide dimutase as control group, while PFE group had higher tocopherol content and glutathione peroxidase activity and lower lipid peroxide contents and superoxide dismutase activity than control group. On the other hand, changes in the values of PFO group were opposite to those of PFE group. Differences in the values among groups were more pronounced as feeding period became longer.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.785-794
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• 2020

Food Codex regulations have set freshness limits for oils used to fry food, such as potato and fish products, and fried food itself; however, no such freshness limits have been set for meat products, such as sweet and sour pork. The freshness standard suggest that acid values (AVs) and peroxide values (POVs) for frying oil should be less than 2.5 and 50, respectively, whereas AVs and POVs for common fried food should be less than 5.0 and 60, respectively. Therefore, in this study, we investigate the effect of the number of frying cycles on oxidation-promoted changes in the oils used to fry sweet and sour pork and fried food itself during repeated frying over 10 d by determining their AVs and POVs, which were found to be highly correlated. Soybean, canola, palm, and pork lard oils could be reused approximately 37, 32, 58, and 87 times, respectively, to fry sweet and sour pork based on oil freshness, and 78, 78, 81, and 286 times, respectively, based on the freshness of fried food. Our data may help establish food-quality regulations for oils used to fry animal-based foods.

• Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.231-235
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• 2010

The effects of various natural antioxidant sources on oxidation of olive flounder (Paralichthys olivaceus) and fish diet during storage was determined. Juvenile fish were distributed among 18 flow-through tanks (40 fish per tank). Six experimental diets were prepared in triplicate: control (CT), antitox (AT), green tea extract (GE), fig extract (FE), Haeroc product (HP) and by-product of green tea (BG). The experimental diets were stored at two temperatures: room temperature ($26.8^{\circ}C$) for 14 days and frozen ($-30^{\circ}C$) for 16 weeks. Thirty fish were sampled from each tank at the end of the 8-week feeding trial. Whole bodies of fish were homogenized and stored in a home freezer ($-9.6^{\circ}C$) for 24 weeks. Acid values (AVs) and peroxide values (POVs) of the diets and frozen fish during storage were monitored. AVs of the experimental diets tended to increase with the storage period except for that of the HP diet at room temperature. POVs from FE, CT, and BG diets peaked at day 7 and then decreased through the remainder of the experiment. AVs of the experimental diets and fish increased with time at $-30^{\circ}C$ and $-9.6^{\circ}C$. Results of this study show that by-products of green tea and Haeroc product seem to have potential as antioxidants in fish feed to inhibit oxidation of both the feed and fish during storage.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• Journal of the Korean Applied Science and Technology
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• v.16 no.2
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• pp.143-146
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• 1999

In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, Quercetin in the Onion ethanolic extract was affected as eliminator of the Mercury, Lead, and Cadmium.Abstracts In order to study for Onion ethanolic extract on the Heavy Metal Elimination and antioxidation, the peroxide values of oil and eliminated metal were analyzed. The results are follows: It was very effective as a retardant for autoxidation processing of the soybean and olive oil by the Onion ethanolic extract. Quercetin in the Onion ethanolic extract was affected as a ligand for chelating with some metals. Through out this study, quercetin in the Onion ethanolic extract was affected as eliminator of the mercury, lead, and cadmium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.552-556
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• 2001

The purpose of this study was to investigate the antioxidant effect of aqueous green tea(AGT) on soybean oil. AGT was freeze-dried and 20% of the freeze-dried aqueous green tea powder (AGTP) was added to soybean oil in the quantities of 0.5%, 1% and 5%. Soybean oil without the addition of AGTP was used as a control. Soybean oil with 0.02% butylated hydroxytoluen(BHT) was used as another experimental sample. Each sample was stored at 6$0^{\circ}C$ for 15 days. The oxidation of these samples was determined by measuring the acid value (AV), peroxide value (POV), and thiobarbituric acid (TBA) value. The result showed that the acid values were lowest in 0.02% BHT, followed by the 0.5% AGTP, 1% AGTP, 5% AGTP and finally the control. When AGTP was added, the peroxide value was lower than both the control and 0.02% BHT. The lowest TBA values were in the 0.5% AGTP followed by 0.02% BHT, 1% AGTP, 5% AGTP and the control, respectively. The 5% AGTP (285 min), 1% AGTP (249 min) and 0.5% AGTP (238) demonstrated longer induction periods, compared to the control (204 min) and the BHT (229 min) by Rancimat method.

• Journal of the Korean Applied Science and Technology
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• v.20 no.2
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• pp.141-147
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• 2003

Oxidized polyethylene wax is obtained by oxidation of polyethylene wax and it is composed of various chemicals, e.g., fatty acid, alcohol, ketone and ester. The application of oxidized polyethylene wax is determined by the composition of these chemical substances. In this basic study we observed the basic reaction parameters of time, temperature, oxygen concentration and catalysts on the oxidation reaction of low molecular weight polyethylene(PE wax) by analyzing the acid value, physical and chemical properties of oxidized PE wax to develop a new oxidation process. Acid values are increased with temperature increase in the rage of $150^{\circ}C^{\sim}180^{\circ}C$ but decreased beyond 190$^{\circ}C$. Acid values are also increased with oxygen concentration. As the oxidation reaction proceeds the molecular weight and softening points of oxidation products are decreased by cracking reaction, but the viscosities are increased. To observe the crystallinity of oxidation products SEM experiment was performed. To obtain a high acid-value product in a mild condition, we adopted free radical catalysts and the acid value of the product using catalyst was higher than the product obtained without catalyst in the same reaction condition. The effective initiators were dicumyl peroxide(DCPO), t-butylperoxy-2-ethyl hexanoate(HOPO) and benzoyl peroxide(BPO) having long half-life.

• Journal of Environmental Science International
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• v.17 no.10
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• pp.1139-1146
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• 2008

To investigate the functional properties and the antioxidant effect of pine needle(Pinus densiflora), the pine needle extract was obtained with methanol and its functionality was measured by spectrophotometric method, and the antioxidant experiment on soybean oil was carried out by the active oxygen method. The extraction yield of pine needle with 99% methanol was about 19%, the total flavonoid content of the pine needle-methanol extract was 11.32 mg/g on dry basis and the superoxide dismutase-like activity was 94.3%. The nitrite scavenging ability of the extract was pH dependent with the values of 77.44% at pH 1.2, 48.45% at pH 3.0 and 11.04% at pH 6.0, respectively. The peroxide value was 92.6 meq/kg at 5% dosage, 138.4 meq/kg at 2% dosage of the extract on 8 oxidation days. The period of the peroxide value to be 100 mg/kg was 4.9, 6.3 and 8.5 days at control, 2% and 5% dosage of extract, respectively. And the relative antioxidant effectiveness of the extract was 27.9% and 72.3% increase at 2% and 5% dosage, respectively, compared to control. The thiobarbituric acid value showed few differences within 4 oxidation days, but with the dosage of the extract it fairly decreased with considerable antioxidant effect to control above 4 days.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.4
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• pp.635-641
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• 1992

The influence of alkaline hydrogen peroxide (AHP) and peracetic acid treatment on in sacco digestion of aspen was evaluated in three non-lactating ruminally cannulated Holstein cows fed a diet containing 90% forage and 10% concentrate on a DM basis. AHP treatment decreased lignin concentration by 40 to 60% resulting in increased concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF) and cellulose. Lignin concentrations in peracetic acid treated samples were less than 10% of values for control samples. In sacco disappearance rates of aspen DM, NDF, ADF and cellulose increased (p<.05) with AHP and peracetic acid treatment. Effective degradability of DM, NDF, ADF and cellulose were determined at a ruminal outflow rate of $.05h^{-1}$. Effective degradabilities of AHP treated aspen were approximately three-fold greater and peracetic acid treated samples five-fold greater than untreated control samples. For all parameters measured, peracetic acid treatment resulted in higher (p<.05) digestion coefficients than AHP treated aspen. Results demonstrate that peracetic acid or AHP treatment can enhance the nutritive value of aspen sawdust for ruminants to a level comparable to that reported for many forages.