• Journal of the East Asian Society of Dietary Life
• /
• v.21 no.5
• /
• pp.723-730
• /
• 2011

Soybean oil used to fry French fries, chicken nuggets, and donuts was exposed to high temperature at $180^{\circ}C$ for 72 h. The effects of frying foods on the thermooxidative stability of soybean oil were evaluated by determining the contents of free fatty acids, peroxides, total polar compounds, and conjugated dienoic acids, and by analyzing dielectric constant, refractive index, iodine value, smoke point, and fatty acid composition. The contents of free fatty acids, total polar compounds, conjugated dienoic acids, dielectric constant, and refractive index increased, whereas iodine value, smoke point, and U/S ratio of fatty acids composition decreased with frying time. All samples of frying oils after 72 h presented free fatty acid contents of below 2.0% and total polar compounds of below 25%, which were within the legal limits. However, peroxide values of frying oils were not directly correlated with frying time. The type of fried food affected the thermooxidative stability of the frying oils, with chicken nuggets being more stable in thermooxidation than French fries and donust. Among physiochemical indicators of frying oil quality, a rapid method including dielectric constant and refractive index can be used in quantity food production.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2002.04a
• /
• pp.221-226
• /
• 2002

This paper presents the thermal characteristics analysis of a high-speed HMC(horizontal machining center) with spindle speed of 30,000rpm and fried rate of 40m/min. The spindle speed is achieved by introducing angular contact ball bearings, oil-jet lubrication method, oil jacket cooling method, and so on. The spindle system is a motor-separated type composed of the main spindle and sub-spindle which are mechanically connected by the flexible coupling. The spindles are supported by two front and rear bearings, and the built-in motor is located between the front to and rear bearings of the sub-spindle. The thermal analysis model of HMC is constructed by the finite element method, and the thermal characteristics in the design stage are estimated based on temperature distribution and heat flow under the various testing conditions related to spindle speed and feed rate.

• Tribology and Lubricants
• /
• v.25 no.2
• /
• pp.125-131
• /
• 2009

Biodiesel produced from triglyceride which is main component of animal fats and vegetable oils by methanolysis was known for excellent lubricity. In this study, the lubricity of 12 kinds of biodiesel come from vegetable oils were analyzed using HFRR(High frequency reciprocating rig). The biodiesel synthesized from soybean oil has best lubricity by $153{\mu}m$ of wear scar in HFRR and used fried oil's biodiesel has slightly low lubricity by $299{\mu}m$. Also we have found that the lubricity of diesel was improved when mixing ratio of soybean biodiesel was increased in base diesel.

• Korean Journal of Food Science and Technology
• /
• v.49 no.1
• /
• pp.50-55
• /
• 2017

The purpose of this study was to investigate the effect of frying number on oxidative changes in edible oils and fried foods. According to the frying number, the extracted edible oils from pork cutlet and fried potato were used as experimental samples. The Ministry of Food and Drug Safety (MFDS) regulations permit edible oils to have <2.5 mg KOH/g of acid value and <50 meq/kg of peroxide value in food. However, there are no regulations for edible oils used to fry livestock. Animal foods contain protein and fat, and should be held to a different standard than ordinary food. Therefore, we present basic information and suggest the establishment of regulations for livestock frying oil and fried livestock.

• Journal of the East Asian Society of Dietary Life
• /
• v.8 no.4
• /
• pp.536-553
• /
• 1998

Korea supposed the place of origin of soybean. Although it is speculated that it was edible in the era of the Three Kingdoms(A.D. 5-9C), there is no documentary evidence. The first record about the edibility of tofu was written down in the Goryeo dynasty, and there was several documents that tofu was exported to China and Japan in the Chosun dynasty due to excellent manufacture skills for tofu. Tofu has been a good source of protein as a food for the common people, though there were not many traditional kinds. Especially, tofu has been an important vegetarian foodstuff in a Buddist temple, and has been used for vegetable soup and skewered greens necessary for the sacrificial rites of the humbler class as well as of the royal court. We frequently made sliced raw tofu and fried tofu, and it was used for broil, stew, and casserole as well as stuffing. In addition, tofu and its bean-curd dregs were applied of making soy. In China it is assumed that tofu has been eatable since the time of the Han(AD. 1C). Chinese tofu and its products are various and generally 20 different varieties are used. There are many dishes applied of tofu. salted and plain tofu were used as Chinese appetizer dishes. Plain, salted, skinned or deep-fried tofu was stir-fried in an hot oiled pan with vegetables, meats and fishes. Additionally, there are a variety of tofu dishes utilized stewing, frying, steaming, and soup cookeries. Tofu first appeared in the era of the Nara(8C) of Japan and was come into wide use in the era of the Aedo(Tokyo). In Japan tofu and its products are various and introduced in Shojin cookeries prevalent in the Buddist temples. It is especially noticeable that frozen or skinned tofu was used for these. Japanese tofu cooking is more delicate than Korean and Chinese ones, and Japanese people do not use oil. Instead, they in general utilize steaming and broiling cookeries. In the western countries the history of tofu edibility is short. However, their practical application of tofu in the dietary life is very positive.

• Journal of the Korean Dietetic Association
• /
• v.21 no.4
• /
• pp.320-332
• /
• 2015

This study investigated the main dishes of menus at university faculty cafeterias to understand current lunch menu trends. A sample of 1040 menus was collected from Internet homepages of 52 universities between March and May, 2014. The main dishes of menus were categorized into six groups based on main ingredients and cooking methods. The most frequently served main dish ingredient was pork followed by fish/seafood, and poultry. Pork dishes and chicken dishes were mainly roasted, pan fried, or deep fried with various carbohydrate ingredients to bulk them up. Large amounts of chili pepper, corn syrup, and oil were added to improve the bland flavor of these dishes, which contain starchy ingredients. In contrast to pork dishes or chicken dishes, 40.2% of beef dishes was served in a more traditional way as soup. Fewer kinds of fish or seafood were used, and the cooking methods also lacked diversity. In conclusion, main dish menus at university faculty cafeterias have undergone changes in terms of ingredients and cooking methods. Meat dishes cooked using traditional methods are becoming less common, especially for pork and chicken dishes, which are quite sweet, salty, and spicy. Extensive use of carbohydrate ingredients was found in some meat dishes and side dishes in one-dish meals.

• Korean Journal of Food Science and Technology
• /
• v.16 no.2
• /
• pp.218-222
• /
• 1984

Browning pattern was developed in aqueous solutions of glucose/glycine mixture under controlled conditions. Browning pattern was definitely influenced by pH of medium and concentration of reactants. Filter paper disks were immersed in diluted solutions of glucose/glycine system and fried in cooking oil. Concentrations of reactants only affected browning pattern of fried filter paper disks and pH effect was obscured at high temperatures. Amorphous brown precipitate was obtained from the lowest pH medium of glucose/glycine system. An attempt was made to characterize the brown pigment produced in the present model system.

• Journal of the Korean Society of Food Culture
• /
• v.24 no.4
• /
• pp.426-432
• /
• 2009

The quality of baked Yackwa with rice bran oil varied with dipping temperature (80 and 25$^{\circ}C$) and dipping time (5, 10, and 15 minutes at 80$^{\circ}C$, and 60, 90, and 120 minutes at 25$^{\circ}C$). The moisture content and hardness of baked Yackwa increased and decreased, respectively, with dipping time. The expansion ratio increased with time when baked Yackwa was dipped at 80$^{\circ}C$, but decreased with time when dipped at 25$^{\circ}C$. Flavor and color were optimal for product dipped at 80$^{\circ}C$ for 15 minutes followed those dipped at 25$^{\circ}C$ for 120 minutes; the dipping conditions produced no significant difference in the degree of expension, aroma, texture, and overall quality. Baked Yackwa showed better results than fried Yackwa in sensory evaluation.

• Korean journal of food and cookery science
• /
• v.7 no.2
• /
• pp.41-49
• /
• 1991

Yackwa is a Korean traditional fried cake made by went flour, sesame oil and honey. This study was investigated to the Rice-Yackwa for the purpose of the improvement of Yackwa's quality and rice consumption by sensory evaluation and instrumental measurement. It was resulted that taste and flavor of Rice-Yackwas were better than those of Wheat-Yackwa by sensory evaluation. We tested whether the mesh of the rice (80,100,120) and swelling agents (baking power, soju : Korean alcholic beverage) affected the Rice-Yackwa's swelling or not. In result, not by soju but by baking powder Rice-Yackwas were swelled. But Rice-Yackwa was so hard, that the Yackwas were made by the two different compositions of mixed flour (rice : wheat ; 75:25, 50:50) exibited softer than those made by rice. The hardness of 25 g% mixed flour Yackwa was improved. And we examined the softening effect on rice and mixed flour Yackwa by the increasing storage periods (1, 2, 3, 5 days). Rice-Yackwa's hardness was changed more greatly than Wheat-Yackwa's by storage periods. In addition to we inspected the effluence of sesame oil in the pross of frying. Sesame oil (40%) was drown out the Rice-Yackwa.

• Journal of the Korean Society of Food Culture
• /
• v.2 no.1
• /
• pp.33-43
• /
• 1987

The cooking processes of Yackwa writen in 27 Korean books were reviewed. The changes of the names, shapes, materials and methods of dough, and the methods of frying, the materials and methods of soaking, garnishes were reviewed based on the historical literatures. 1. The changes of names of Yackwa were Yackwa, Kwajul, Chokwa and the shapes were bird, animal, round or cubic. The diameter was about 3.5cm, and thickness was from 0.5cm to 1.5cm. 2. The major ingredients of Yackwa were flour, honey, sesame oil and alcohol beverages. Sometimes, soybean powder and rice powder were used instead of flour, and chochung, sugar water, sugar syrup were used instead of honey. Sesame oil was usually used but salad oil were used occasionally. Usually pure liquor, distilled spirits, rice wine, cloudy and coarse rice wine, whisky were used as alcoholic ingredient and water was used at boiling state. Sesame and sesame salt, ginger and ginger juice, pepper powder, pine nuts powder, salt were used as minor ingredients. 3. Though the flour was kneaded extensively or gently, the latter was peculier since 1940. 4. The dough was fried in oil at $120{\sim}160^{\circ}C$ for $5{\sim}15$ minutes. at that time, The shape will be broken if temperature of oil is too low and too harden if temperature is too high. 5. Fried dough was soaked in honey before 1940, but thereafter other sweeteners, such as chochung, syrup were also used. Ginger juice, dried ginger, citron juice were used for flavor. 6. For enhancing the flavor and softening excess oil was removed from the fried Yackwa, and then it was soaked in honey. 7. The garnishes of Yackwa were pine nuts powder, cinnamon powder, sugar, etc.