• 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.

• 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 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 Science and Technology
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• v.31 no.4
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• pp.919-923
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• 1999

The edible portions of saury were cooked by pan frying, deep fat frying, steaming and microwave cooking to compare the compositions of fatty acids in cooked fish with those in raw fish. The total lipid in saury studied varied by each fish but ranged from 21.87% to 30.63%. The distribution of each fatty acid (average) was in order; $C_{22:1}\;(21.75%)>C_{20:1}\;(15.81%)>C_{16:0}\;(11.75%)>C_{22:6}\;(DHA,\;10.61%)>C_{14:0}\;(7.04%)>C_{20:5}\;(EPA,\;5.13%)$. The average ratio of PUFA (polyunsaturated fatty acids)/SFA (saturated fatty acids) in saury fillet was 1.07 and that of n-3/n-6 was 9.15, which showed saury might be a good source for PUFA including n-3 fatty acids. Comparing the effects of cooking on EPA and DHA, two of the most important n-3 PUFA, the decreasing rate of EPA were 6.98% (pan frying), 26.93% (deep fat frying), 1.16% (steaming) and 15.12% (microwave cooking), respectively. The decreasing rate of DHA ware 4.30% (pan frying), 15.99% (deep fat frying), 3.26% (steaming) and 9.56% (microwave cooking). This study showed that both EPA and DHA were reduced by steaming least, and pan frying, microwave cooking, deep fat frying most, in order.

• 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.

• Korean Journal of Human Ecology
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• v.22 no.3
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• pp.485-492
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• 2013

The temperature changes of dumpling(mandu) during cooking process were examined and the effects of time-temperature and/or time-size interactions on internal temperature were studied. Mandu was purchased from local markets and classified by its weight(small, medium, and large). Boiling, steaming, pan frying, and deep fat frying were adopted. Internal temperature was measured with a food thermometer in every one minute. The internal temperature of mandu increased over time in every cooking process(p<0.05). After three minutes the internal temperature of mandu in boiling, pan frying, and deep fat frying reached over at $74^{\circ}C$, which is high enough temperature to kill the harmful bacteria, but not in steaming. The internal temperature of mandu was significantly affected by cooking time, size, and both in boiling, steaming, and deep fat frying(p<0.05). There were significant differences between the internal and surface temperatures of mandu in the cooking processes except pan frying in three minutes(p<0.05). The results of this study indicate three minutes' cooking of the mandu by boiling, pan frying, and deep fat frying is safe enough to eat. However, longer steaming time is needed in order to reach safe temperature. This study also indicates the cooking time and size of mandu appear to be major factors in determining the internal temperature achieved at $74^{\circ}C$. More research is needed to check time to reach a safe temperature in the cooking process of mandu by steaming.

• 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 environmental and Sanitary engineering
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• v.4 no.1 s.6
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• pp.29-36
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• 1989

The purpose of this investigation was performed for chemical values related to rancidity of fat and oils extracted from deep-frying food in Seoul. The samples were collected according to kinds of fat and oils, sampling sites and food stuffs for frying. The results were as follows 1. The most used frying oils were rice bran oil $(37.0\%)$ and shortening $(29.6\%)$, followed by rapeseed oil $(14.8\%)$. 2. The chemical values related to rancidity of fat and oils extracted from deep-frying foods were the next on average. Acid value-1.42, peoxide value-39.82, dinitrophenyl hydrazine value-16.73 thiobarbituric acid value-0.263. However the highest value among oils was showed in rice bran oil and the lowest value was shortening. 3. For the classification of sampling sites, acid value and peroxide value of samples of the markets were found higher than them of environs of school and roadside, and the differences between them were significant (P> 0.01), while dinitrophenyl hydrazine value and thiobar bituric acid value were not showed the significant differences. 4. For the classification of foodstuffs for frying, there were not recognized significant differences among all kinds of them.

• 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.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.181-189
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• 2008

In this study, changes in total trans fatty acid (tFA) and fat contents were determined in soybean oil, shortening, and olive oil after potato sticks were fried 30 consecutive times, respectively. Prior to frying, the potato sticks contained 3.8% fat, with 43.2% tFAs, After the first frying in soybean oil, the total tFA content of the potato sticks sharply decreased to 3.2%, and then it gradually increased to 8.1 % after 30 consecutive times of frying. However, the total fat content of the potato sticks, fried in soybean oil increased to 15.2% after the first frying and thereafter it decreased to 9.75% with 30 repeated episodes of frying. When the potato sticks were fried in olive oil, similar changes in tFA and fat contents were shown; while such changes were not observed when shortening was used. After 30 consecutive frying events, the tFA contents in the soybean oil and olive oil increased to 4.15 and 5.75%, respectively; however, such an increase was not observed in the shortening. One can assume that most of the tFAs in the fried oils were from the potato sticks, which contained relatively high tFA content during the repeated deep-frying process.