• Food Engineering Progress
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• v.21 no.4
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• pp.375-382
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• 2017

The purpose of this study was to examine the effect of different types of frying oil on the quality of yakgwa such as expansion rate, color, moisture content and rheological properties. Yakgwa fried with corn oil showed the highest expansion in width and length, and rice bran oil in height. With regard to the overall expansion rate, yakgwa fried with rice bran had the highest value. As for lightness and yellowness, yakgwa fried with soybean oil had the highest lightness (34.74), while yakgwa fried with grape seed oil had the lowest lightness (29.82). As for redness, however, no significant difference was found. Regarding fat content, yakgwa fried with rice bran oil showed the highest value with 18.91%, while yakgwa fried with corn oil and canola oil showed the lowest value. No difference was found in moisture content according to the type of frying oil. In relation to the acid value, yagkwa with soybean oil showed the lowest value of $0.24{\pm}0.66$; as for peroxide value, yagkwa fried with rice bran oil showed the lowest value of $3.59{\pm}1.74meq/kg$. No difference was found in hardness, cohesiveness and resilience according to the type of frying oil. Yagkwa fried with corn oil and canola oil showed the lowest value in terms of adhesiveness and chewiness, respectively. The results of the sensory evaluation showed not significance difference in overall preference, but yakgwa fried with rice bran oil had the highest value of $5.93{\pm}1.87$.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.941-953
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• 2019

Biodiesels are being explored as a clean energy alternative to regular diesel, which causes pollution. In this study, the optimum conditions for producing biodiesel (BD) by combining beef tallow, an animal waste resource with a high saturated fatty acid content, and corn oil, a vegetable oil with a high unsaturated fatty acid content, were investigated, and the fuel properties were analyzed. Furthermore, Multivariate Analysis of Variance (MANOVA) was used to verify the optimum conditions for producing biodiesel. The influences of control factors, such as the oil blend ratio and methanol to oil molar ratio, on the fatty acid methyl ester and biodiesel production yield were investigated. As a result, the optimum condition for producing blended biodiesel was verified to be tallow to corn oil blend ratio of 7 : 3 (TACO7) and a methanol to oil molar ratio of 14 : 1. Moreover, the interaction between the oil blend ratio and the methanol to oil molar ratio has the most crucial effects on the production of oil blended biodiesel. In conclusion, the analysis results of the fuel properties of TACO7 BD satisfied the BD quality standard, and thus, the viability of BD blended with waste tallow as fuel was verified.

• Journal of the Korean Society of Food Culture
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• v.21 no.6
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• pp.679-684
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• 2006

In this experiment, I used three samples of oils. The oils that I used were hydrated soybean oil, pure soybean oil and regular soybean oil. The group of rice was fried in the each sample of oil that had not been used for a few seconds. Rice was used after frying at 230-235$^{\circ}C$ every four hours terms and total frying hours was 12 hours. The hydrated soybean oils was least affected in rancidity. The other two oils were more affected in rancidity than the hydrated soybean oil. However, the trans fatty acid in hydrated soybean oil was 36.5%. The diameter of the poped rice that was fried in pure soybean oil and regular soybean oil that had been used 12 for hours was reduced while the diameter of the popped rice fried in the hydrated soybean oil was not reduced. Also, the groups of rice fried in the pure and the regular soybean oil that had been used for 12 hours reduced the hardness in rice while the group that fried in the hydrated soybean oil at the 12th hour kept the hardness well. In sensory evaluation, rancidity order was found apparently in the pure soybean oil that had been used for 12 hour and in the regular soybean oil that have been used for eight hours and 12 hours. Only the hydrated soybean oil did not have distinctive rancidity order at all. The degree of the crispiness was reduced in the pure soybean oil and in the regular soybean oil at 12th hour frying. However, the hydrated soybean oil preserved the crispiness well until the end of 12 hours of frying. In overall preference test, the pure and regular soybean oil that had been used for 12 hour were not preferable. In conclusion, I found that the group fried in the hydrated soybean oil was better in every evaluation than the groups fried in the pure soybean oil and in regular soybean oil. The hydrated Soybean oil may be better to be used in food manufacturing if the trans fatty acid in the hydrated soybean oil can be reduced.

• Journal of the Korean Applied Science and Technology
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• v.32 no.2
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• pp.194-201
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• 2015

A lubricant used in the transport sector have been developed for the purpose of improving vehicle performance. To improve the engine oil for some terrible conditions, various studies have been conducted to improve vehicle performance. There are limitations in development of lubricant for the economic point, but various additives have beed developed in the technical point. Recently, government tried to prohibit reckless use of additives in base oil because of the environmental issues. The institutionalized quality standards of the additives has been estabilished. In this study, physicochemical properties and environmental effect of vehicle engine oils in domestic sector were investigated.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.4
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• pp.85-91
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• 2015

Current world aircraft industry studies on the precision of the product are in active progress. Particularly in terms of improving the quality of processed products in terms of the surface roughness of the dimensional accuracy, fatigue strength, and corrosion resistance, which affect a lot of research on surface roughness, has been investigated. In this study of aluminum alloy, 7075 aircraft aluminum is used in a cutting CNC lathe machine for the cutting speed and feed rate according to the cutting experiments that were conducted. Additionally, the machine tool of the cooling method soluble cutting oil, insoluble cutting oil by cooling, and cooling the workpiece by cutting surface roughness will be investigated. Through the method and soluble cutting oil coolant cooled by the cutting speed increases, the value of surface roughness showed a regular result. Tool nose radius of 0.8 mm than 0.4 mm picture of when approximately 50 of the surface roughness values were less.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.110-116
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• 2020

Aircraft hydraulic oil reservoirs made with aluminum 7075 have an anodized coating to enable airtightness and corrosion resistance. To maintain a stable oil pressure, the internal surface roughness of the reservoir should be less than approximately 0.2 ㎛. To this end, precision polishing must be performed. However, ensuring the processing quality is challenging, as most polishing operations are performed manually, owing to which, the inner surface roughness is not uniform, and the product quality is irregular. Therefore, we developed a special superfinishing machine to realize the efficient inner polishing of an aircraft hydraulic oil reservoir, by using an abrasive film to improve the process throughput and uniformity. In the experiment involving the superfinishing of an anodized aluminum 7075 cylinder specimen by using the proposed machine, a higher surface roughness than that achieved in the repetitive manual polishing process could be realized.

• Food Science of Animal Resources
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• v.37 no.3
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• pp.376-384
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• 2017

The objective of this study was to investigate the effect of using gelled emulsion (olive oil 46%, inulin 9%, gelatin 3%) as fat replacer on some quality parameters of chicken patties. For this purpose GE, prepared with olive oil, gelatin and inulin was replaced with beef fat at a level of 0%, 25%, 50%, 100% (C, G25, G50, G100). In this study syneresis, thermal stability, centrifuge and creaming stability of gelled emulsion were analyzed. Chemical composition, technological paramerers (cooking yield, water holding capacity, diameter reduction, fat and moisture retention) and textural and sensory properites were evaluated in comparision to control patties. High thermal stability was recorded in GE (93%), also creaming stability results showed that GE protected its stability without any turbidity and separation of the layer. The complete replacement of beef fat with GE showed detrimental effect on all investigated cooking characteristics except fat retention. Replacement of beef fat with GE at a level of 50% resulted similar cooking characteristics with C samples. Color parameters of samples were affected by GE addition, higher CIE $b^*$ values observed with respect to GE concentration. The presence of GE significantly affected textural behaviors of samples (p<0.05). Our results showed that GE prepared with inulin and olive oil is a viable fat replacer for the manufacture of chicken patty.

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.256-266
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• 2014

The purpose of this study was to determine the optimal mixing conditions of soybean oil and bread crumbs mixture for pork patty. The experiment was designed according to the central composite design of response surface methodology. There were ten experimental points, including two replicates for soybean oil and bread crumbs. The physicochemical and mechanical analyses of each sample, including pH, cooking loss, thickness increase, moisture content, lightness, hardness, adhesiveness, springiness, chewiness, and gumminess showed significant differences (p<0.05). The results of sensory evaluation showed significant differences in tenderness, juiciness, and overall quality (p<0.05). The optimum formulation calculated by numerical and graphical method was 13.61 g of soybean oil and 6.35 g of bread crumbs. The results obtained in this study will be useful to the meat industry, which tends to decrease the saturated fatty acid content with a concomitant enrichment in the unsaturated fatty acids content.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.2
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• pp.106-112
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• 2008

In this paper, the experimental results on evaporation heat transfer characteristics were reported for a micro-fin tube using $CO_2$. An experimental refrigerant loop had been established to measure the evaporation heat transfer coefficient and pressure drop of $CO_2$. Experiments were conducted for mass fluxes, heat fluxes, saturation temperatures and PAG oil concentrations. With increasing the heat flux and the saturation temperature, the evaporation heat transfer coefficient increased. At the higher mass flux, however, the exit vapor quality of the micro-fin tube was to be lower. The peak of the heat transfer coefficient was shifted toward low quality region. The evaporation pressure drop increased as the mass flux increased and the saturation temperature decreased. As PAG oil concentration increased, the evaporation heat transfer coefficient decreased and the dryout was delayed by oil addition.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1580-1585
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• 2004

A quality of a refrigeration cycle and a reliability of a compressor can be reduced if a refrigerant including excessive lubricating oil is exhausted from the compressor. Thus, the analysis of the oil behavior inside the compressor is required to prevent the problem. A tested rotary compressor with visualization windows has been manufactured in this study to investigate the oil behavior using developed visualization techniques. The oil behaviors at various operating conditions have been quantified to obtain the relationship with the outlet pressure inside the compressor. Also, the effect of the operating conditions on the quantity of the exhausted oil from the rotary compressor has been investigated using the visualization technique.