• 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.30 no.1
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• pp.77-81
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• 1998

Rice germ oils were extracted from common and dried rice germ $(80^{\circ}C,\;6\;hr)$, and their oxidative stabilities were evaluated by measuring acid value, peroxide value and fatty acid composition during storage at $40^{\circ}C\;and\;60^{\circ}C$. The acid values of all lipids were slightly changed during storage, but peroxide values (POV) were greatly dependent on storage temperature. The POVs of the dried germ oil and the refined rice bran oil were 146.2 meq/kg and 15.1 meq/kg, respectively after 31 days storage at $40^{\circ}C$. However after 24 days of storage at $60^{\circ}C$, the POVs of the dried germ oil and the refined rice bran oil were 151.7 meq/kg oil and 219.6 meq/kg oil, respectively. Major fatty acids were linoleic (39.8%) and oleic acid (34.7%) in rice germ oil, and oleic (40.1%) and linoleic acid (38.1%) in rice bran oil. The major fatty acid compositions were not greatly influenced by drying and storage temperature but linoleic acid decreased about half during storage.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.4
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• pp.527-534
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• 2012

This study investigated changes in the quality properties of deep frying oil and fried chickens according to frying number. Acid values of frying oil and fried chicken after frying 110 chickens were 2.27 and 1.90, respectively. The peroxide values of frying oil did not increase uniformly as frying number increased. Conjugated dienoic acid value of frying oil and fried chicken after frying 110 chickens were 0.70 and 0.44, respectively. Regarding the fatty acid composition after frying 110 chickens, linoleic and linolenic acids decreased, whereas palmitic, stearic, and oleic acids increased. Contents of trans fatty acids in frying oil and fried chicken after frying 110 chickens were 0.75% and 0.45%, respectively. Contents of benzo [a] pyrene in frying oil and fried chicken after frying 110 chickens were 2.20 and 2.19 ${\mu}g/kg$, respectively. The quality properties of frying oil and fried chickens significantly decreased after frying 60 chickens.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.464-469
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• 1996

Pleurotus ostreatus was extracted with hexane, ethanol and water to test the antioxidative activity on soybean oil. The extraction yield was the highest in the water fraction. The total sugar was higher in ethanol and water fractions, While the total phenolic substances were relatively higher in the hexane fraction. The antioxidative effects of the extracts on the oxidation of soybean oil during storage at 60 and $100^{\circ}C$ were studies. The antioxidative effects of ethanol extracts of both fruit body and mycelia of pleurotus ostreatus were higher than those of water and hexane extracts. The antioxidative effects of Pleurotus ostreatus extracts (3,000ppm) were higher than the artificial antioxidant (200ppm), BHA and BHT, during storage at 60 and $100^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.472-477
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• 2012

As people are being exposed to many types of fast food, rancid oil is a factor affecting public health. Monitoring of rancidity in frying oils needs to be done adequately. The chemical methods that are currently used require long periods of time and expertise. The development of a device that quickly and easily measures rancidity would be helpful to manage rancidity in frying oils adequately. Due to the fact that carbon nanotube (CNT) is sensitive to acid value, we used CNT as a sensing material for detecting oil rancidity. Polyethylenimine (PEI) was coated on CNT for stable measurements. Experiments were conducted at $100^{\circ}C$ after samples were cooled from $180^{\circ}C$. The results showed a strong correlation between acid values and resistances using CNT sensors. As the acid value of oils increased, the resistance of CNT sensors increased. Development of sensors using CNT may make it possible to determine the rancidity of frying oils in real-time and on site.

• The Korean Journal of Food And Nutrition
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• v.16 no.1
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• pp.1-6
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• 2003

This study was attempted to analyze nutritional composition and nutritional balance of domestic and affiliated company of foreign group weaning food. The results were as follows: The proximate compositions were 61%∼70% carbohydrate, 14%∼16% protein, 2.5%∼3.2% ash and 8%∼15% lipid. Leucine content was the highest among all essential amino acids in all test weaning foods. The P/S and linoleic acid / linolenic acid ratio of domestic weaning foods were higher than those of affiliated company of foreign group weaning food. The peroxide values of H, M, S and N product were 13.9 meq/kg oil, 1.1 meq/kg oil, 5.4 meq/kg oil and 14.8 meq/kg oil, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.503-508
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• 1991

The salted and dried mullet(Mugil Japonicus) roe had about 42% of protein and 41% of lipid content as major compoments. Therefore the lipid oxidation and the deterioration of protein occurred during drying and storage periods. In order to keep the good quality of the dried roe, acid, peroxide, thiobarbituric acid value and the contitutional amino acid were studied in the different drying air velocities at the conditions of 60% R.H. and $20^{\circ}C$ of drying air temperature. The optimum air velocity showed 2m/sec, which was excellently superior to the lipid and protein quality than those of other air velocities on the dried mullet roe. The drying period shortened from 20 days in the conventional processing method to 7 days in the modified processing method that had 2m/sec of drying air velocity. The drying rate curve had only a falling-rate drying period and not to have a constant-rate drying period.

• Journal of the Korean Society of Food Culture
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• v.21 no.2
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• pp.166-170
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• 2006

Soybean oil (SBO) was carried out deodorization at 4 factors as controlled maximum deodorizing temperature (DT), vacuum degree (VD), cycle time (CT) and treating amount of stripping steam (TASS). The results were as follows, acid value (AV), peroxide value (PV) and trans fatty acid content (TFAC) in produced deodorized SBO. Obtained deodorized SBO at high DT had the lower AV, PV, but TFAC was increased relatively. A suitable level of VD and TASS was 4.0 torr and 2.0%(w/w), than the longer CT was appeared a superior quality level. As a result, the best deodorizing conditions in SBO for lower TFAC were maximum DT; $235^{\circ}C$, VD;4.0torr, CT; $14{\sim}15min$ and TASS; 2.0% (w/w). Deodorizing conditions for lower TFAC in deodorizing of SBO was the major factor, more than lower DT was difficult because of the others quality factors.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1314-1319
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• 2005

The purpose of this study was to investigate the antioxidative effects of Lycii fructus powder (LFP) solvent extracts and Maejakgwa made with LFP. The solvent extracts of LFP were added to soybean oil in the quantity of $0.05\%$. The solvents used were methanol, ethanol, ethyl acetate and petroleum ether. Soybean oil without the addition of LFP was used as a negative control. Soybean oil with $0.02\%$ butylated hydroxytolune (BHT) and $\alpha$-tocopherol were used as positive controls. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation level of these samples was determined by measuring the acid value, peroxide value and thiobarbituric acid (TBA) value. The oxidation level of solvent extracts of $0.05\%$ LFP was lower than both the negative control and $\alpha$-tocopherol. Especially, methanol extract of $0.05\%$ LFP was the lowest. The methanol extract (320 min) and ethanol extract (316 min) demonstrated longer induction periods, compared to the control (253 min), $\alpha$- tocopherol (255 min) and BHT (309 min) by Rancimat method. Acid value of Maejakgwa was increased during the storage time, but it was lower in Maejakgwa made with LFP than in the control group. Peroxide value was increased rapidly for 30 days and then decreased. TBA value was lower in Maejakgwa made with 3, 6, $9\%$ LFP than in those made with $15\%$ LFP and the control.