• 대한가정학회지
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• 제11권4호
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• pp.374-387
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• 1973

This work was carried out to investigate the changes of chemical and physical properties of frying oil, when it was used many times continuously without adding new oil. Four kinds of frying oil (soybean oil, rapeseed oil, shortening and crude lard) and slices of potato and Aji (kind of fish) were used in the experiment under the condition of home cooking. Obtained results were as in the followings. 1. Acid values and peroxide values of each frying oil were under the safety level (A. V = 1.5, Po. V = 50) except crude lard, when frying works were continuously repeated five times for 50 days. 2. Changes of saponification values of each frying oil showed a decreasing tendency except the crude lard. But in cases, stickiness or clothing of oil were not seen in frying even at the five times frying. 3. Changes of optical density of each frying oil showed a decreasing tendency in all cases, according to the times of frying, especially at the first time frying. 4. Maximum heights of the shamp of each frying oil and their shampholding activites when heated, were slowly increased according to the times of frying. 5. Without concerning the cooking condition (kinds of oil, cooking material and repeating times of frying) decrement of oil in once frying was almost exactly 20g per 150g. 6. Decrements of cooking material in all cases of frying showed almost constant values, potato to be 40% and Aji 20%. 7. Differences of smoke point between new and old oil (frying repeated 5 times) showed also almost constant values. Liquid oil (soybean oil and rapeseed oil) showed number (6-$10^{\circ}C$), on the contrally solid oil (shortening and crude lard) a high number (10-$25^{\circ}C$). 8. Results of public tastic for the frying products were almost good even in that of a low five times frying, but the products, of third time frying with crude lard were expressed as disagreeable.

• 한국식품조리과학회지
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• 제28권4호
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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.

• 대한가정학회지
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• 제19권2호
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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.

• 대한가정학회지
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• 제24권4호
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• pp.75-84
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• 1986

The followings are the results of the study on decomposition of oil during the process of frying hot-dogs with soybean oil. First, the oil was heated repeatedly for six days, four hours two session per day. Then the oil was observed when heated under identical condition except for the exclusion of the frying ingredients. And the oil itself was heated constantly for a period of 48 hours. 1. The AV and Carbonyl Value of all frying oils increased with each use (but the oil in which frying ingredients with all other oils) 2. All frying oils showed a tendency to increase initially, then decrease their POV and TBA Number during their heating process. 3. The IV of all oils showed a slight decrease except for oil with frying ingredients added, with showed a substantial decrease. 4. Oil with frying ingredients showed a substantial increase in its oxidized fatty acid level, and others showed a tendency to increase according to the frying time. Decomposition of soybe an oil during the process of frying hot-dogs was studied. Three treatment was performed first, the oil was heated (with hot-dogs) repeatedly four hours in each session, two sessions per day for six days. Second, the oil was heated without hot-dogs under identical condition, Third, the oil was heated constantly for 48 hours.

• 동아시아식생활학회지
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• 제22권4호
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• pp.527-534
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• 2012

본 연구에서는 닭튀김을 일정기간 반복 재사용했을 때, 닭튀김 횟수에 따른 튀김유 및 튀김닭의 품질 저하 정도를 비교, 검토하였다. 닭 110마리 튀긴 후의 튀김유 및 튀김닭의 산가는 각각 2.27 및 1.90이었으며, 공액 이중 산가는 각각 0.70 및 0.44였다. 과산화물가는 튀김 횟수에 따른 일률적인 증가를 보이지 않았다. 닭 110마리 튀긴 후 튀김유의 지방산조성을 보면, 리놀레산과 리놀렌산의 함량은 감소하고, 팔미트산과 스테아르산, 올레산의 함량은 상대적으로 증가하였다. 110마리 튀긴 후의 튀김유와 튀김닭의 트랜스지방산의 함량은 각각 0.75 및 0.45%이었으며, 벤조피렌의 함량은 각각 2.20 및 2.19 ${\mu}g/kg$으로 거의 차이가 없었다. 전체적으로 튀김유와 튀김닭의 품질은 닭 60마리 튀긴 후 현저하게 감소되었다.

• 한국식품조리과학회지
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• 제18권3호
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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.

• 한국식품조리과학회지
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• 제14권2호
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• pp.177-181
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• 1998

감자 및 닭튀김의 튀김회수에 따른 튀김유의 물리화학적 특성의 변화를 경시적으로 측정하였다. 튀김유의 온도변화는 닭튀김의 경우보다 감자튀김의 경우 더 큰 것으로 나타났다. 튀김과정 중에 튀김재료인 냉동감자의 중량감소는 21.9% 정도이었으며 닭튀김의 경우 닭튀김물의 중량감소는 12.8% 정도인 것으로 나타내었다. 튀김횟수인 15회까지의 감자 튀김유와 닭튀김유의 산가는 튀김횟수에 따라 지속적으로 증가하였으며 이들의 산가는 모두 0.6이하로 나타났다. 튀김횟수인 15회까지의 감자와 닭튀김유의 과산화물가는 일률적으로 증가하지 않았다. 튀김횟수에 따른 감자와 닭튀김유의 요오드가의 변화는 거의 보이지 않았다. 감자 및 닭튀김시 튀김유의 색상은 튀김횟수가 증가함에 따라 R(red)및 Y(yellow)가 뚜렷이 증가되었으며, 닭튀김유는 감자튀김유보다 훨씬 높았다. 튀김횟수가 증가함에 따라 linoleic acid의 감소와 oleic acid의 상대적인 증가를 나타내었다. Linoleic acid의 감소와 oleic acid의 증가는 감자튀김유보다는 닭튀김유에서 더욱 큰 것으로 나타났다.

• 한국식품조리과학회지
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• 제9권4호
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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.

• 한국식품조리과학회지
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• 제16권4호
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• pp.328-335
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• 2000

학교급식에서 대량튀김시 많이 이용되는 냉동식품중 선호도가 가장 높은 돈까스를 튀길 때 튀김유 사용방법과 한 번 사용한 튀김유의 저장기간에 따른 이화학적 특성을 조사한 결과는 다음과 같았다. 1. 산가는 방법 A의 강우 신선한 기름의 0.14에서 튀기는 횟수가 증가할수록 점차증가하여 5회 튀긴 후에는 0.24로 증가하였으며, 방빈 B, C도 모두 같은 경향이었다. 이 때 방법 B에서 신선한 기름을 첨가하여 다시 튀기기 시작할 때의 산가는 감소하다가 튀김횟수가 증가함에 따라 방법 C보다 오히려 큰 폭으로 증가하였다. 과산화물가는 신선한 기름에서 0.7이었고 A, B, C세 가지 방법 모두 튀기는 횟수와 한 번 사용 후 저장기간이 증가할수록 증가하였다. 방법 B의 과산화물가도 산가와 같은 경향이었다. 한편 요드가와 검화가는 세 가지 방법에서 모두 튀기는 횟수와 한 번 사용 후 저장기간이 증가할수록 감소하였다. 지방산 조성의 변화를 보면 가열함에 따라 한 번 사용하는 튀김유의 저장기간이 증가할수록 포화지방산은 약간 증가한 반면 불포화지방산 중 특히 linoleic acid는 감소하였다. 2. 점도는 튀김횟수가 증가함에 따라 세 가지 방법에서 모두 약간 증가하는 경향을 보였는데, 한 번 사용한 튀김유의 저장기간이 길어짐에 따라 증가하였다. 색도도 튀김유의 사용횟수와 한 번 사용한 튀김유의 저장기간이 증가할수록 적색도와 황색도가 현저하게 증가하였다. 본 실험의 조건하에서는 학교급식에서 대량튀김시 주로 사용되는 튀김유의 사용방법과 한 번 사용한 튀김유의 저장기간은 튀김유의 이화학적 특성에 영향을 미치는 것으로 나타났다. 이상의 결과로 볼 때 물론 튀김유를 한번 쓰고 버리는 방법 A의 경우가 가장 바람직하겠지만 보관 후 한 번 더 사용하는 방법인 B와 C의 경우도 보건복지부에서 규정한 튀김유의 사용가능한 산가와 과산화물가의 기준보다는 훨씬 낮아 안전함을 알 수 있었다.

• 한국응용과학기술학회지
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• 제10권2호
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• pp.7-10
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• 1993

감자튀김시 Silicone oil의 튀김유 산화방지효과에 대하여 검토하였다. 1. 감자튀김시 SO가 첨가된 튀김유가 SO가 첨가되지 않은 튀김유에 비하여 튀김유의 AV, Dielectiric constant, Smoke point, Oxidative stability 저하지연효과가 좋았으며, SO의 첨가량이 $1{\sim}10ppm$사이에 있어서는 튀김초기에는 큰 차이가 없으나 튀김시간이 길어질수록 SO의 첨가량이 많은 것이 산화에 대한 안정성이 높았다. 2. 감자튀김의 경우 SO를 $1{\sim}10ppm$의 사이로 첨가하면 튀김시 튀김유의 열화를 실용적으로 지연시킬 수 있었다.