• Korean Journal of Medicinal Crop Science
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• v.11 no.3
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• pp.236-245
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• 2003

The study was performed for elucidating angiotensin converting enzyme (ACE) inhibitory activity and comparing antioxidative activity of Panax ginseng extracts prepared at different conditions. Total phenolic content, inhibitory activity on ACE and antioxidative effects were tested on 10 ethanolic extracts and correlation coefficient between total phenolic content and physiological activity was calculated. Yield and total phenolic content of 50% ethanolic extract prepared at $85^{\circ}C$ exhibited the highest value as 42.52% and 0.82%, respectively. Among the fractions obtained from 50% ethanolic extract prepared at room temperature, water fraction showed the highest value in yield as 72.08% and ethyl acetate fraction did in total phenolic content as 6.59%. In the test on ACE inhibitory activity, 50% ethanolic extract obtained at room temperature indicated the strongest effect of 93.8% which was higher than 85.2% of commercialized ACE inhibitor and solvent fractions showed potent inhibitory activity in order of hexane fraction, diethyl ether fraction, ethyl acetate fraction, butanol fraction and water fraction at concentration of $4000{\mu}g/ml$. 50% Ethanolic extract prepared at $85^{\circ}C$ had the most potent inhibition effect on human LDL oxidation as 78.2% at $200{\mu}g/ml$ and the other extracts also did above 60%. Diethyl ether fraction and ethyl acetate fraction showed strong inhibition activity $(34.38%{\sim}78.13%)$ on LDL oxidation at concentration of $10{\sim}200\;{\mu}g/ml$. From the statistical analysis via SAS program, correlation coefficient between total phenolic content and ACE inhibitory effect was 0.6353 at P<0.05. Conclusively, this report showed that the most efficient extraction condition for elevating inhibitory activity on ACE and LDL oxidation, phenolic content and yield from Panax ginseng was 50% ethanol extraction at room temperature or high temperature condition. And Panax ginseng would be used for preventing hypertension or atheroscrelosis for man via inhibitory action on ACE and LDL oxidation.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.184-191
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• 2002

We investigated the role of vitamin C or rutin on neuropathy and lung damage of diabetic mellitus(DM) rats. Norepinephrine content was significantly decreased in sciatic nerves of DM rats compared with non-DM controls but vitamin C had no effect on decreases of norepinephrine. 2,4-dinitrophenylhydrazine (DNPH) incorporation, which is biomarker of protein oxidation, was increased in sciatic nerve of DM rats as compared with normal control. However, vitamin C had no effects on increases of DNPH incorporation . We measured the content of conjugated dienes (CD) as a biomarker of lipid oxidation in sciatic nerve. CD was increased in DM as compared with normal control, Vitamin C or rutin had no effects on increases of CD. However, Rutin plus vitamin C significantly decreased the content of CD as compared with CIM rats. In lung of DM rats, DNPH incorporation or CD was increased as compared with normal control. Vitamin C or Rutin had no effects on increases of CD However, Rutin plus vitamin C significantly decreased the content of DNPH incorporation or CD in lung tissue. Vitamin C caused marked pathological changes such as the increases of parenchyma and the thickening of alveolar septa in the lung of DM. Rutin had protective effects on the pathological changes in the lung of DM rats. In conclusion, Vitamin C had no effects on oxidative parameter, such as DNPH incorporation or CD, and on the decreases of norepinephrine content in DM rats. Vitamin C caused the marked pathological changes in the lung of DM rats but rutin had protective efforts against the pathological changes.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.294-303
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• 2019

To extend the shelf-life of chicken breast meat, samples were treated with gel-packs containing slow-released $ClO_2$ gas at 7-15 ppm for 8 days at $4^{\circ}C$. And the changes in lipid oxidation and taste compounds of the samples were investigated. TBARS value of the chicken breast was slightly increased during storage. TBARS value of gas treatments was similar to the control during storage. There were 14 fatty acids in the chicken breast. And there was no change in the fatty acid composition during storage, and there was no significant difference between the control and gas treatments. The content of free amino acids was gradually increased during storage. The content of free amino acids were not significantly different between the control and gas treatments during storage. The content of GMP in the control and gas treatments were decreased during storage. However, gas treatments showed slightly higher content than that of control. AMP was not significantly different between the control and gas treatments. IMP gradually decreased during storage and the content of inosine and hypoxanthine was increased. IMP, inosine and hypoxanthine contents of gas treatment were similar to control, but the control tended to change more rapidly than those of gas treatments.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.639-648
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• 2015

Some materials of fatty acids in the biodiesel affect the physical/chemical properties like density, kinematic viscosity, total acid number and oxidation stability by forming an organic fatty acid in combination with oxygen in the air. To solve the problem of the oxidative stability of biodiesel, various kinds of antioxidant has added and analyze the characteristics of the physical/chemical property changes by the addition of antioxidant. Oxidation stability increased by the increase of additives content. The TBHQ among the seven kinds of the additives showed the best performance. Also, 4 kinds of additives like propyl gallate, butyl-amine and pyrogallo has showed above 10 hr of oxidation stability at the addition of 500 ppm. In case of pyrogallo, this is not appropriate as an additive to suitable quality standards of total acid number. TBHA, DTBHQ of hydroquinone was satisfied with the quality standard of oxidation stability but the target of this research(above 10 hr) did not satisfied with oxidation stability. Propyl gallate is also a suitable at the quality standards of total acid number but it was shown not to be an appropriate to the additives due to increasing the total acid number by increasing of the content of additives at the addition of 500 ppm.

• Journal of the Korean Ceramic Society
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• v.31 no.7
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• pp.759-766
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• 1994

The effect of additives on properties of unfired Al2O3-C bricks were investigated. The increase of carbon content and the addition of MgO or spinel improved the resistances against spalling and corrosion of unfired Al2O3-C bricks. Also, the oxidation resistance of unfired Al2O3-C brick was increased by adopting complex metals of Al and Si in spite of the increase of carbon content.

• Korean Journal of Community Nutrition
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• v.20 no.6
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• pp.468-478
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• 2015

Objectives: The objective of this study was to evaluate the thermic effects, the macronutrient oxidation rates and the satiety of medium-chain triglycerides (MCT). Methods: The thermic effects of two meals containing MCT or long-chain triglycerides (LCT) were compared in ten healthy men (mean age $24.4{\pm}2.9years$). Energy content of the meal was 30% of resting metabolic rate of each subject. Metabolic rate and macronutrient oxidation rate were measured before the meals and for 6 hours after the meals by indirect calorimetry. Satiety was estimated by using visual analogue scales (VAS) at 8 times (before the meal and for 6 hours after meal). Results: Total thermic effect of MCT meal (42.8 kcal, 8.0% of energy intake) was significantly higher than that (26.8 kcal, 5.1% of energy intake) of the LCT meal. Mean postprandial oxygen consumption was also significantly different between the two types of meals (MCT meal: $0.29{\pm}0.35L/min$, LCT meal: $0.28{\pm}0.27L/min$). There were no significant differences in total postprandial carbohydrate and fat oxidation rates between the two meals. However, from 30 to 120 minutes after consumption of meals, the fat oxidation rate of MCT meal was significantly higher than that of the LCT meal. Comparison of satiety values (hunger, fullness and appetite) between the two meals showed that MCT meal maintained satiety for a longer time than the LCT meal. Conclusions: This study showed the possibility that long-term substitution of MCT for LCT would produce weight loss if energy intake remained constant.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.9
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• pp.1336-1344
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• 2014

The effects of various packaging systems, vacuum packaging (VACP), medium oxygen-modified atmosphere packaging (50% $O_2/20%$ $CO_2/30%$ $N_2$, MOMAP), MOMAP combined with vacuum skin packaging (VSP-MOMAP), high oxygen-MAP (80% $O_2/20%$ $CO_2/30%$ $N_2$, HOMAP), and HOMAP combined with VSP (VSP-HOMAP), on the activity of antioxidant enzyme, and oxidation and color stabilities in sliced Hanwoo (Korean cattle) beef loin were investigated at $4^{\circ}C$ for 14 d. Higher (p<0.05) superoxide dismutase activity and total reducing ability were maintained in VSP-MOMAP beef than in HOMAP beef. Lipid oxidation (2-thiobarbituric acid reactive substances, TBARS) was significantly (p<0.05) retarded in MOMAP, VSP-MOMAP, and VSP-HOMAP beef compared with HOMAP beef. Production of nonheme iron content was lower (p<0.05) in VSP-MOMAP beef than in HOMAP beef. Red color ($a^*$) was kept higher (p<0.05) in VSP-MOMAP beef compared with MOMAP, HOMAP, and VSP-HOMAP beef. However, VACP beef was found to have the most positive effects on the antioxidant activity, oxidation and red color stabilities among the various packaged beef. These findings suggested that VSP-MOMAP was second to VACP in improving oxidation and color stabilities in sliced beef loin during chill storage.

• Journal of the Korean institute of surface engineering
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• v.35 no.6
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• pp.415-421
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• 2002

Ti-Si-N coating layers were codeposited on silicon wafer substrates by a DC reactive magnetron sputtering technique using separate titanium and silicon targets in $N_2$/Ar gas mixtures. The oxidation behavior of Ti-Si-N coating layers containing 4.0 at.%, 10.0 at.%, and 27.3 at.% Si was investigated at temperatures ranging from 600 to $960^{\circ}C$. The coating layers containing 4.0 at.% Si became fast oxidized from $600^{\circ}C$ while the coating layers containing 10.0 at.% Si had oxidation resistance up to $800^{\circ}C$. It was concluded that an increase in Si content to a level of 10.0 at.% led to the formation of finer TiN grains and a uniformly distributed amorphous Si3N4 phase along grain boundaries, which acted as efficient diffusion barriers against oxidation. However, the coating layers containing 27.3 at.% Si showed relatively low oxidation resistance compared with those containing 10.0 at.% Si. This phenomenon would be explained by the existence of free Si which was not nitrified in the coating layers containing 27.3 at.% Si.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.14-20
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• 2010

Naturally present antioxidants, tocopherols, carotenoids, and phospholipids in the bran and germ oils from Keumkang (K-WBG oil) and Dark Northern Spring wheats (DNS-WBG oil) were determined during storage under 1700 lux light at $5^{\circ}C$ by HPLC. Oil oxidation was monitored by peroxide values (POV) and conjugated dienoic acid content. The results showed that antioxidants were degraded during storage of the WBG oils under light, with higher degradation rates for carotenoids and phospholipids in the K-WBG oil compared to the DNS-WBG oil. Light increased oil oxidation and the rate of oxidation was higher in K-WBG oil than in the DNS-WBG oil. There was a high correlation between POV and residual amounts of antioxidants during photo-oxidation, with phospholipids showing the greatest effects on POV. This study suggests that a higher amount and lower degradation rate of phospholipids in the DNS-WBG oil contributed to its higher photo-oxidative stability compared to the K-WBG oil.

• Korean journal of food and cookery science
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• v.18 no.2
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• pp.200-205
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• 2002

Corn starch was modified by the oxidation with sodium hypochlorite(NaOCl) and the changes in the distribution of molecular weight were examined. Corn starch was oxidized with 0.25, 0.5, 0.75, 1.0, and 1.5% active Cl/g of starch at pH 7.0 and 25$^{\circ}C$ for 10 min. Oxidation of corn starch caused a change in the molecular weight distribution of amylopectin. The fraction of highest molecular weight in native starch decreased gradually and the fraction of lower molecular weight increased with increasing oxidation. Also, λ$\sub$max/ and iodine binding capacities of oxidized starches decreased and the soluble carbohydrate content increased by oxidation. The differential scanning calorimetric results of oxidized starches showed that the temperature and enthalpies of gelatinization were not changed by oxidation; however, the more the starch was oxidized, the greater the extent of retrogradation.