• Applied Biological Chemistry
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• v.43 no.2
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• pp.110-115
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• 2000

This study was carried out to investigate the effect of extracts from garlic on the formation of nitrosamine, nitrosomorphorine, the nitrite scavenging ability and the antioxidant activity. The extracts from garlic made the nitrite scavenging ability higher at low pH than at high pH. Especially ethanol extracts from garlic resulted in 89.6% of nitrite scavenging ability at pH 1.2. They were also more effective in the electron donating and antioxidant abilities than water extracts in expressing as the reduction of ${\alpha},{\alpha}-diphenyl-{\beta}-picrylhydrazyl$(DPPH) and peroxide value(POV), respectively. Inhibitory effect of nitrosamine formation by ethanol extract from garlic was excellently more than 80% at pH 1.2 and 3.0, but only 29.9% at pH 6.0. This meant that the inhibition of nitrosamine formation is pH dependent.

• Journal of the Korean Society of Food Culture
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• v.12 no.2
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• pp.195-200
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• 1997

The purposes of this study were to investigate the Maillard reactions of some oligosaccharides with lysine and the antioxidative effects of the ethanol extracts from their reaction mixtures on the soybean oil. The Maillard reactions were carried out of 2% oligosaccharides such as palatinose (PN), fructooligosaccharide (FO), isomaltooligosaccharide (IMO) with 2% lysine (L) for 24 hours heating at 60, 80, $100^{\circ}C$. The color intensity of Maillard reaction mixtures were determined by UV-VIS spectrophotometer upon reaction time and temperature. And the antioxidative effects on the soybean oil of each ethanol extract from Maillard reaction mixture of each oligosaccharide were measured by peroxide value (POV). POV's of soybean oil including reaction extracts were determined regularly every 2 days during 20 days storaged at $60{\pm}1^{\circ}C$. The results were obtained as follows: 1. The color intensity of the Maillard reaction mixtures were raised highly as the browning temperature and time increased. The color intensity of PN L browning mixture was the highest. The order of high color intensity at $100^{\circ}C$ was PN L>FO L>Glu L>IMO L. 2. Comparing the antioxidative effect of Maillard reaction product (at $100^{\circ}C$, for 12 hours) of each oligosaccharide to that of BHT and TBHQ, the order of high antioxidative effect was TBHQ>IMO L>BHT>Glu L>PN L>FO L. 3. From these results, it was known that PN L shown as high brown color intensity was appeared low antioxidative effect, while IMO L shown as low brown color intensity was appeared high antioxidative effect. So, it was recognized that there was no relation between brown color intensity and antioxidative effect.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.127-134
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• 2014

This study was performed to evaluate the effects of sesame oil addition to a tuna oil-enriched emulsion during chlorophyll-photosensitized oxidation. The emulsion principally consisted of tocopherol-stripped canola and tuna oil with or without sesame oil, acetic acid, phospholipids, and xanthan gum. Chlorophyll b was added to promote the production of singlet oxygen upon exposure to light. The oxidation of oil in the emulsion was evaluated by determining the peroxide value (POV) and conjugated dienoic acid (CDA) contents. Concentrations of minor compounds in the emulsion were monitored. Increasing POV and CDA contents in the emulsion were paralleled with decreased docosahexaenoic acid during oxidation, and oxidation was inhibited by the addition of sesame oil. Chlorophyll, polyphenols, tocopherol, and phospholipids were degraded during oxidation of the emulsion; however, their degradation was slowed down by the addition of sesame oil. Lignans in the emulsions containing added sesame oil were barely changed, suggesting that they quenched singlet oxygen physically. Polyphenols were the most effective in improving the stability of tuna oil-enriched emulsions during chlorophyll-photosensitized oxidation.

• Korean Journal of Food Science and Technology
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• v.43 no.6
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• pp.711-718
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• 2011

Effects of heating conditions and seed roasting on the lipid oxidation and antioxidants of perilla seeds were studied. Perilla seeds, that were unroasted or roasted at $180^{\circ}C$ for 20 min, were ground and heated over steam at $100^{\circ}C/1$ atm or at $135^{\circ}C/2$ atm. Lipid oxidation was evaluated by peroxide value, conjugated dienoic acids contents, and fatty acid composition. Tocopherols and polyphenols were also determined. Lipid oxidation of perilla seeds was higher during heating at $135^{\circ}C/2$ atm than at $100^{\circ}C/1$ atm, and the oxidation rate was lower in unroasted seeds than in roasted seeds. Degradation of tocopherols and polyphenols in perilla seeds during heating was faster under high pressure and temperature, and was decreased by seed roasting. Contribution of polyphenols to the oxidative stability of perilla seeds during heating was higher than that of tocopherols, suggesting polyphenols and seed roasting as important factors in lipid oxidation of perilla seeds.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.881-895
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• 2020

The objective of this study was to assess antioxidant activities of leaves and fruit powder of Cudrania tricuspidata (CT) with different particle sizes (crude, 500 ㎛, 150 ㎛), and determine the physicochemical properties and microbial counts of pork patties with various levels of CT fruit powder (CTFP) during refrigerated storage. Total phenolic content of crude leaves had the highest value of 3.54 g/100 g (p<0.05). Overall, CT leaves (CTLP) had higher total phenolic content than CTFP (p<0.05). 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of CTFP was higher than that of CTLP (p<0.05), which showed higher iron chelating ability and reducing power than CTFP (p<0.05). After pork patties were manufactured with 0.5% and 1.0% of CTFP at 500 ㎛, pH, color values, thiobarbituric acid reactive substance (TBARS), and peroxide values (POV) were then measured. The addition of CTFP into pork patties significantly (p<0.05) increased redness and yellowness values of patties. TBARS values of pork patties containing CTFP were lower (p<0.05) than those of CTFP-0 patties after 10 days of storage. Pork patties added with CTFP showed no significant (p>0.05) difference TBARS values among different storage periods. POV values of pork patties containing CTFP were lower than those of the control from 3 days up to the end of refrigerated storage (p<0.05). These results suggest that CTFP could be used as a natural antioxidant to retard lipid oxidation in meat products during refrigerated storage.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.902-908
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• 1995

Oxidative factors of lipid in the roasted laver Porphyra tenera(RL) and roasted-seasoned laver(R-SL) depending on various light sources, water activities, packaging materials and storage temperatures were investigated by peroxide value and color. Major fatty acids of RL were 46.4% eicosapentaenoic acid and 14.9% palmitic acid. Lipid oxidation was decreased in order of darkness, incandescent and fluorescent, decreased sharply with the decrease of water activity and temperature, and also reduced by the packaging material with strong barriers of water vapor, oxygen and light. From kinetics of lipid oxidation, it was supposed that oxidation of R-SL was three times faster than RL. On the other hand, reduction of the total chlorophyll content in RL was stronger than R-SL.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.294-300
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• 2001

Effect of bean water concentration and incubation time of Yukwa paste as well as packaging method on the quality of Yukwa was investigated. Quality loss in Yukwa during storage was dependent on the packaging method such as bamboo packaging at $30^{\circ}C$, nitrogen packaging at $30^{\circ}C$ and LDPE packaging at $-18^{\circ}C$. Peroxide value increased with bean water concentration, but showed no significant difference by incubation time. The hardness of Yukwa decreased with the increase of bean water concentration, incubation time, and storage time but showed no significant difference by packaging method. Sensory evaluation after storage for 3 months showed that Yukwa color was significantly influenced by packaging method and bean water concentration. The volume was also significantly influenced by bean water concentration and incubation time. Off-flavor showed significant difference by storage method. Tenderness, taste and overall desirability showed significant difference by bean water concentration. Crispness showed significant difference by storage method and bean water concentration.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.255-260
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• 1990

The effects of different concentrations of tocopherols on the oxidation stability of evening primrose oil (EPO) in the dark $(35{\pm}2^{\circ}C)$ were evaluated by some physicochemical characteristics such as peroxide, conjugated diene value and fatty acid composition. The results of the present study were as follows; Alpha-tocopherol at all concentrations (0.02%, 0.05%, 0.10%) showed a prooxidant effect during autoxidation of EPO. This prooxidant activity of alpha-tocopherol increased as its concentration increased rapidly. Delta-tocopherol showed antioxidant activity as its concentration increases at an early stage of storage. But the activity was fairly poor antioxidant activity and was not greater than antioxidant activity of BHT. However, the antioxidant effect of delta-tocopherol and BHT showed no apparent differences as compared with result of none.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.266-271
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• 1990

Yukwa(Korean traditional puffed rice snack) puffed by vegetable oil was evaluated its shelf-life and monitored its physicochemical changes during long term storage. And air puffing instead of oil was tested for substitution of puffing medium. The shelf-life of oil puffed Yukwa was less than 4 weeks at $30^{\circ}C$ by peroxide value and negligible changes in physical texture was detected after 9 weeks storge. There was a possibility to apply air puffing method for Yukwa making and its optimum temperature was around $250^{\circ}C$. Air puffed Yukwa was a little less expansion rate, same level of hardness and high brittleness compared with oil puffed . Sensory evaluation of air puffed Yukwa was as same as air puffed in odour, firmness and texture but overall taste was less score probably causing by oil used which need a impovement for air puffed Yukwa. No differences in structure of both Yukwa observed by SEM was showed.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.4
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• pp.443-454
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• 2006

Purpose: This study aims to get the fundamental data which is necessary to the development direction of implant surface treatment hereafter, based on the understanding the surface structure and properties of titanium which is suitable for the absorption of initial tissue fluid by researching effects of additional surface treatments fir sandblasted with large git and acid-etched(SLA) titanium on surface micro-roughness, static wettability, fibronectin adsorption Materials and Method: In the Control groups, the commercial pure titanium disks which is 10mm in diameter and 2mm in thickness were treated with HCI after sandblasting with 50$\mu$m $Al_2O_3$. The experiment groups were made an experiment each by being treated with 1) 22.5% nitric acid according to SLA+ASTM F86 protocol, 2) SLA+30% peroxide, 3) SLA+NaOH, 4) SLA+ Oxalic acid, and 5) SLA+600$^{\circ}C$ heating. In each group, the value of Ra and RMS which are the gauges of surface roughness was measured, surface wettability was measured by analyzing with Sessile drop method, and fibronectin adsorption was measured with immunological assay. The significance of each group was verified by (SPSS, ver.10.0 SPSS Inc.) Kruskal-Wallis Test. (α=0.05) And the correlation significance between Surface micro-roughness and surface wettability. surface roughness and fibronectin adsorption, and surface wettability and fibronectin adsorption was tested by Spearman's correlation analysis. Result: All measure groups showed the significant differences in surface micro-roughness, surface wettability, and fibronectin adsorption. (p<0.05) There was no significance in correlation among the surface micro-roughness, surface wettability, and fibronectin adsorption. (p>0.05) Conclusion: Surface micro-roughness and surface wettability rarely affected the absorption of initial tissue fluid on the surface of titanium.