• Korean journal of food and cookery science
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• v.28 no.4
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• pp.443-450
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• 2012

This study was investigated the effect of an oil-water fryer on quality properties of deep frying oil used for chicken. The acid and conjugated dienoic acid values of frying oil using an oil-water fryer were lower than those using a deep fat fryer, whereas the iodine value of frying oil using an oil-water fryer was higher than that using a deep fat fryer. The peroxide values of frying oil did not increase with frying number. Frying oil with an oil-water fryer had lower palmitic acid, stearic acid and oleic acid, and higher linoleic and linolenic acid contents than those with a deep fat fryer. The contents of trans-fatty acids in frying oil using a deep fat fryer and oil-water fryer after frying 110 chickens were 0.75% and 0.47%, respectively. The benzopyrene contents of frying oil using a deep fat fryer and an oil-water fryer after frying 110 chickens were 2.20 and $1.61{\mu}g/kg$, respectively.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.533-541
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• 2001

This research was carried out to obtain the information about the use of deep-fat-fried foods and treatment of oils used for deep-fat-frying at home. Data were obtained through questionnaires from 442 housewives in Chonbuk area. The frequency of taking deep-fat-fried foods was affected by ages and residential area. Average score for the preference of deep-fat-fried foods was 3.60 in the 5 point scale. Fifty three percent of the respondents prepared deep-fat-fried foods by themselves at home. The oil most commonly used for deep-fat-frying was soybean oil followed by com oil. Proper frying temperature was determined by dropping salt or food coating materials into the oil. Oil color was used as a parameter for determining the life of frying oils by 81.2% of the respondents. Most of the respondents appealed to use oils one more time after filtering. For the disposal of used frying oil, 65.7% of the respondents used some kinds of absorbing papers; 16.1% made soaps and 10.7% discarded into a sink. According to correlation analysis, the frequency of taking deep-fat-fried food had positive relationships with housewives's health status, preference for foods prepared with oil and fats and family's preference for deep-fat-fried foods.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.717-723
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• 2006

Chemical characteristics of soybean oil after deep-frying with potato sticks (200 g, 10% w/w of soybean oil) were studied according to the 34 deep-frying times. After consecutive 34 deep-frying, total polyunsaturated FA contents was gradually decreased while the total saturated FA and trans FA were increased. Acid value and peroxide value were increased while iodine value decreased, respectively. The Hunter $L^{\ast}$ value decreased while each $a^{\ast}\;and \;b^{\ast}b$ value were gradually increased. Electronic nose equipped with 12 metal oxide sensors was used for the discrimination of odor pattern of frying oils against the times of deep-trying. The proportions of 1st and 2nd principal component analysis showed 75.97% and 21.23%, respectively. While 6 among total 12 sensors well responded to discrimination of odor in the repented frying oils, suggesting that the odor pattern of each oil after deep-frying would be discriminated against fresh soybean oil, especially after 14 times. From the results, electronic nose could differentiate the degree of quality deterioration of the repeated deep-frying oils.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.46-53
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• 2020

Carrots were deep fat fried with sunflower oil (SO), palm oil (PO), and a blend of palm and sunflower oils (PSO with PO:SO as 2:8 or 4:6) at different temperatures (180 and 190℃) and lengths of time (0.5 to 2.5 min). The quality of deep fat fried carrots was determined by the moisture and fat content, color, conjugated dienoic acid (CDA), hydroperoxide, p-anisidine value, and fatty acid composition. The moisture content of fried carrots decreased with increasing frying time, while the fat content increased. The CDA and p-anisidine values of carrots fried with SO were higher than those fried with PO because of greater unsaturated fatty acids content in SO. PSO was a better choice than SO or PO for deep fat frying carrots in the aspects of oxidative stability and ratio of unsaturated to saturated fatty acids. These results indicate that the quality of deep fat fried carrots depends on the type of oil and frying temperature used, as well as the length of time.

• Korean journal of food and cookery science
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• v.9 no.4
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• pp.293-297
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• 1993

This study aims to seek ways to improve frying stability of soybean oil which is widely used for deep frying while at the same time attempting to develop new frying oil and fat of high quality. Taking soybean oil as a control group, the study fried frozen potatoes with hydrogenated soybean oil with iodine value ranging from 60 to 110 for 15 hours. The test results showed that in frying stability, hydrogenated soybean oil with iodine value of 87 and 63 was superior to normal soybean oil and hydrogenated soybean oil with iodine value of 111(P<0.05). In sensory evaluation, however, no significant difference can be detected among groups(P>0.05). The correlation between physicoche-mical properties and sensory evaluation results was highest for smoke point and viscosity. This study concludes, therefore, that hydrogenated soybean oil with iodine value of 60~90 is better than normal soybean oil as deep-frying oil.

• Journal of the Korean Home Economics Association
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• v.19 no.2
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• pp.213-221
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• 1981

This theiss deals with the effects of addition of silicone oil to the polymerization and oxidation of frying oil in the practical deep fat frying process. The measurement of frying oil stability was carried out under various silicone oil content and compared with controlled frying process. In controlled frying process A.V., C.O.V., TBA, and contents of petroleumether insoluble fatty acids were increased as time was increased. It means thermal oxidized polymerization and hydrolysis of frying oil was occurred. When silicone oil was added to frying oil, it's thermal stability was better than that of the controlled oil and the degree of thermal stability was changed according to the contents of silicone oil. We obtained the highest degree of thermal stability when silicone oil was added 1ppm.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.470-476
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• 2013

The property of deep frying oil is one of the important factors in fried food quality. The purpose of this study is to identify the quality of deep frying oil in continuous usages for 4 days by two types of fryers: traditional deep-fat fryer and modified oil-water fryer. After frying pork cutlets, the frying oil was kept not only for several physical analyses such as color, viscosity, and water content but also for the quality analyses of frying oil, such as free fatty acid, double bond changes and oxidative rancidity formation. The oil fried in a traditional deep-fat fryer was significantly increased in terms of physical values including moisture content, viscosity, and color, compared to those of the modified fryer, continuously for 4 days. The oil fried by a traditional deep-fat fryer exhibited a significant increase in its free fatty acid content compared to that fried by a modified oil-water fryer, while the iodine value was significantly decreased in the oil fried by a traditional deep-fat fryer when compared to control oil and oil fried by the modified oil-water fryer. In the peroxide value as an indicator of primary oxidation products, the oil fried by both fryers was significantly increased till the second day but decreased in value after the third day because of unstable hydroperoxide decomposition. The p-anicidine value is used as an indicator of secondary oxidation products, the oil fried in a traditional deep-fat fryer was significantly increased in value compared to that of a modified oil-water fryer.

• 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.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.318-322
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• 1994

Aluminium alloy, comprising water, silicone manganese and porous aluminium carrier added into soybean oil in order to investigated its effect on polar lipid content, polymer content, conjugated dienoic acid and free fatty acid value during deep-fat frying at 185$^{\circ}C$. Increase rates of polar lipid and polymer content of the frying ell were reduced about one thirds of the oil without aluminium alloy during deep-fat frying. The aluminium alloy, however, have no significantly effect to inhibit the increase of conjugated dienoic acid and free fatty acid value. Treatment of the frying oil with aluminium alloy was found to be able to inhibit polymer and polar lipid formation.

• Korean journal of food and cookery science
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• v.18 no.3
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• pp.340-348
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• 2002

Changes in the physicochemical properties of frying oil after single or repeated use in foodservice establishments were studied. The experiment was designed to simulate the practical frying practice based on a survey from the dieticians in the food service establishments. Used oils came from the single frying of mackerel and the sequential frying of 1) potato and mackerel, 2) battered pork and mackerel, and 3) potato, battered pork, and mackerel. The used oil samples were analyzed and compared with the fresh one. Oil quality parameters such as acid value, peroxide value, thiobarbituric acid value, iodine value, viscosity, and color were measured at each step of deep-fat frying. The physicochemical properties of the frying oils have been more or less affected by the frying conditions. However, the used oils resulted from the experimental trials were within the range of acceptance as indicated by the acid and peroxide values.