• Korean Journal of Food Science and Technology
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• v.17 no.3
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• pp.180-185
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• 1985

The alkali refined rice bran oil (ARBO) and the esterified rice bran oil (ERBO) with glycerol were compared for their thermal stabilities at $150^{\circ}C$ and $180^{\circ}C$, respectively. The acid value gradually increased in ARBO during heating period but increased slowly in ERBO-2 and declined gradually in ERBO-1. The peroxide value was somewhat fluctuated during heating period, and the maximum peroxide value in all samples was 13.3 meq/kg. TBA value was sharply increased for the first 10 hr. heating and slowed down thereafter for all samples but ERBO were intensely colored after the heat treatment. The TG ratio of the oils after 90 hr. heating was not different at $150^{\circ}C$ but ERBO was 2-7% higher ratio of TG than ARBO at $180^{\circ}C$. The oxidative stability of ARBO was twice higher than ERBO according to the result of active oxygen test.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.568-571
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• 1991

This study was designed to select the most stable oil among vegetable oils for mayonnaise preparation on lipid oxidation when blended with perilla oil. Oxidative stabilities of perilla oil, soybean oil, rapeseed oil, corn oil, sunflower oil and perilla blended oils (blended perilla oil with other vegetable oil in a equal weight rate) were tested. Among the perilla blended oils, perilla blended soybean oil was the most effective on oxidative stability. This may be concerned with the fact that the content of natural antioxidant, tocopherol, is higher than that of other oils. Mayonnaise was prepared by using both perilla oil and perilla blended soybean oil. Variations of POV and tocopherol content of mayonnaise during storage at $37^{\circ}C$ were compared. The changes in POV and tocopherol content in the mayonnaise of perilla blended soybean oil were less than those of perilla oil. This result suggested that the usage of perilla blended soybean oil instead of perilla oil itself is possible in the manufacturing of mayonnaise.

• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.313-318
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• 1986

Four model systems of ground cooked meat (GCM), GCM-water (W), GCM-brine (B) and GCM-soybean sauce (S) were prepared and stored at $6^{\circ}C$ for 5 weeks. The oxidative behavior of lipids in the systems and the antioxidative effects of soybean sauce on the lipid oxidation were studied during the period of storage.Tiobarbituric acid values and peroxide values of the systems of GCM, GCM-B and GCM-W were increased significantly with the storage time, however, those values of GCM-S were hardly changed during the time of t u·eeks storage. The decreases in the contents of dienoic/polyenoic fatty acids of neutral or phospholipid fraction in GCM-S system were found to be the lowest among the systems during the 5 weeks storage. And also the least development of rancid flavor evaluated by sensory score during storage were observed in GCM-S system. These results are suggested that soybean sauce in the systems plays an important role as an antioxidative material on the lipid oxidation.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1045-1050
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• 1998

This study was carried out to investigate the oxidative stability of oils from peril1a seeds roasted at $190^{\circ}C$ for $0{\sim}50$ min. The oxidative stability of perilla oils increased as the roasting time increased. Oxidative stability of perilla oils extracted methanol extracts significantly decreased. When 1.0%(w/w) methanol and hexane fractions prepared from methanol extracts added to the unroasted perilla oils, methanol fractions showed strong antioxidative effects, but hexane fractions showed weak effects. As the roasting time increased, the browning intensity, fluorescence and electron donating ability of methanol extracts, methanol and hexane fractions increased, and those were closely related with antioxidative effects.

• Applied Biological Chemistry
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• v.37 no.3
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• pp.168-174
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• 1994

Effects of filtration and centrifugation on the oxidative stabilities of sesame oils during storage at $70^{\circ}C$ were studied by combination of determining peroxide values and conjugated dienoic acid values of oils and measuring the hexanal formation using headspace gas chromatography. Crude sesame oil from roasted seeds contained more free fatty acids, conjugated dienes, and metals (Fe, Cu, Mg and Zn); on the other hand, higher contents of moisture and ${\gamma}-tocopherol$ were found in the filtered or centrifuged oil. Only filtered oil contained more peroxides than the crude oil in spite of the color advantage of the highest L and b values among three oils. All the oils showed the tendency of increasing in total color difference during storage at $70^{\circ}C$, fatty acid compositions were relatively constant except for decreasing tendency of linoleic acid in filtered oil. No significant difference at 1% in the oxidative stabilities was observed between centrifuged oil and crude oil with higher susceptibility to the oxidation in the filtered oil. Centrifuged sesame oil was the best in the aspect of both oxidative stability and the oil color.

• Applied Chemistry for Engineering
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• v.8 no.6
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• pp.934-938
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• 1997

Acrylic acid was grafted onto the peroxidized cellulose which was stored at room temperature for 20 days after ${\gamma}$-ray irradiation in air. The effect of acids and metallic salts on the grafting yields was determined. The addition of both the acid and metallic salt was found to accelerate the grafting yield much more than the only metallic salt, and the addition of $FeSO_4{\cdot}7H_2O$ led to much higher grafting yield than that of $CuSO_4{\cdot}5H_2O$. The effect of acid on the grafting yield increased by the order $H_2>SO_4>HCl>HNO_3>CH_3COOH$. With the addition of $H_2SO_4$, the grafting yield rapidly increased up to $7{\times}10^{-2}$M, and then levelled off.

• 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.

• Polymer(Korea)
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• v.35 no.2
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• pp.136-140
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• 2011

The plasma resistances of nitrile curable perfluoro elastomer (NT PFE) and peroxide curable PFE (PO PFE) after exposing to $NF_3$ and $O_2$ remote plasmas were investigated by analyzing weight loss and morphology of O-ring made of PFE. The compounds were designed following the typical formulations of O-ring/seal which were applied in semiconductor and LCD production site. They were blended by an open roll mill, and then, O-ring was finally made by hot press molding and oven curing. The weight loss was calculated and morphology was observed for each atmosphere and temperature by a digital weighing machine and SEM. As results, it was confirmed the weight loss and related morphology were meaningfully different according to the cure type of PFE, filler system, and the species of remote plasma.

• Food Science and Preservation
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• v.12 no.1
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• pp.17-22
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• 2005

This study analyzed the change of physical and chemical characteristics on the safflower seed produce coated edible film. L and a value of safflower seed product coated edible film were slowly increased during storage, while b value decreased. Moisture content were increased during storage. Acid valus welt less increased when edible film was ased. Peroxide values were also increased during storage, but peroxide value in products coated sodium caseinate or k-carraggenan was $50\%$ in the control after 30 days of storage. The value of sensual test was higher in products coated sodium caseinate or k-carraggenan than those of control. Coating with sodium caseinate or k-carraggenan was effective for acidification retardation and quality improvement of safflower seed products.

• Food Science and Preservation
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• v.13 no.6
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• pp.726-731
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• 2006

Extract from forty four species of natural plants in Korea were obtained. Each extinct (1,000 ppm) was added into fish oil and their antioxidative activities were screened by rancimat, From the results, seven species including Brassica juncea, Solanum tuberosum, Capsella bursa, Ulums davidiana, Broussonetia kazinoki, Oenanthe javanica, and Rhus chinensis were selected due to their relatively prolonged induction periods. When the concentration (100 - 1,000 ppm) of the selected extract was considered, the most prolonged induction period was observed from Solanum tuberosum throughout the studied concentrations, suggesting that its extinct showed the strongest antioxidative activity against fish oil. In addition, peroxide value (POV) and thiobarbituric acid reactive substance (TBARS) value were considered at $60^{\circ}C$ for 5 days. Among the selected extract, extract from Solanum tuberosum showed the lout POV while the extract from Brassica juncea var showed the least TBARS values after 5 days. Also, the free radical scavenging effect against DPPH radical were studied with the selected extract, showing that the extract from Rhus chinensis was found to be the most effective.