• Journal of the Korean Society of Food Culture
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• v.12 no.1
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• pp.35-40
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• 1997

Effects of frying temperature, kneading degree and ingredients ratio of sesame oil, syrup and sozu on quality characteristics were studied. Mixture experiments were used for the variation of three components. L-value was significantly high at $120^{\circ}C$ and was increased by increasing the kneading degree. a-value was increased by increasing the frying temperature, however there were no significant differences as the kneading degree was changed. Hardness of yackwa was increased by increasing the frying temperature and the kneading degree. Fat absorption rate was decreased as the frying temperature and the kneading degree were increased. Dip syrup absorption rate was increased by decreasing the frying temperature, however there were no significant differences as the kneading degree was changed. There were no clear relationships between color value and ingredients ratio. Hardness of yackwa was increased by increasing the amount of sesame oil and sozu and decreased by increasing the amount of syrup. Fat absorption rate was increased by increasing the amount of sesame oil and syrup. Dip syrup absorption rate was increased by increasing the amount of syrup and by decreasing the amount of sesame oil and sozu.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.265-273
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• 2012

The purpose of this study was to determine the effects of the duration of frying and storage periods on physicochemical characteristics of various oils using at home. The materials used for the study consisted of four kinds of vegetable oils: soybean, canola, extra virgin olive and pure olive oils, and shortening. Chicken breasts were fried in oils heated at $180^{\circ}C$. The oils were stored with or without filtering and reused 3 times, during the 10 day period. The extra virgin and pure olive oils showed higher acid, peroxide value and yellowness than the other oils (p<0.05), but soybean oil showed the highest increase in acid, peroxide value and yellowness with reusing and storage. In sensory evaluation, the chicken breast fried with soybean oils remarkably decreased the overall acceptance. These results suggested that all frying oils are available because acid and peroxide values of the oils are lower than the standard level. However, reusing soybean oil should be noted with caution in that it is very easy to reduce rancidity, and extra virgin olive oil is not appropriate for frying.

• KSBB Journal
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• v.11 no.2
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• pp.159-164
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• 1996

Transesterification of used frying oil was investigated to produce the bio-diesel oil. Experimental conditions included molar ratio of used frying oil to alcohol (1:3, 1:5 and 1:7), concentration of catalyst (0.5, 1.0 and 1.5 wt.%), ippe of catalyst(sodium melhoxide, NaOH and KOH), reaction temperature (30, 45 and $60^{\circ}C$), and types of alcohol(methanol, ethanol and butanol). The conversion of used frying oil increased with the alcohol mixing ratio and with the reaction temperature. The effect of the type of catalysts on conversion was not significant. The highest conversion was obtained when methanol was used as alcohol. Viscosity was a little higher with the ester product over grade #2 diesel oil. But the physical properties improved significantly with transesterification, resulting in similar fuel properties with those obtained for grade #2 diesel fuel.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.231-234
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• 2000

To evaluate the effect of frying times on the oxidative stability of soybean oil and shortening, they were reused up to 10 times and measured by thiobarbituric acid(TBA) value, acid value(AV), peroxide value(POV) and sensory evaluation. As the reusing time was increased, TBA value of "battered pork" fried with shortening showed more sharply increased than that with soybean oil, while the value of shortening, itself, showed more decreased than that of soybean oil. In frying fat, AV and POV increased with the increase of reusing times. Compared with soybean oil, shortening had rapidly increased for POV as reusing time was increased. Among the sensory analyses TBA of "battered pork" with soybean oil and shortening exhibited the highest correlation with flavor and texture, respectively. For the "batgtered pork" fried with soybean oil and shortening, reusing shelf-lives predicted were approximately 9 and 8 times, respectively.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.409-418
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• 1989

The oxidative stability of the ramyon prepared with ricebran oil fortified with ${\alpha}-tocopherol$, BHA, TBHQ, and ascorbyl palmitate+citric acid or blended with palm oil was studied to assess the suitability of the oil as the frying oil. The antioxidants were added to a ricebran oil at 0.02% level, respectively, while blended oils were prepared by adding a palm oil to the ricebran oil at ratios of 3:7, 5:5, and 7:3. Ramyon samples were prepared by frying steamed noodel with the oils. They were stored in dark at $35.0{\pm}0^{\circ}C$. for 90 days. Peroxide, acid, iodine values, dielectric constant, and fatty acid composition of the oils extracted from the samples were determined regularly. The oxidative stability of the extracted oils and storage stability of the samples were estimated from the results of the determinations. ${\alpha}-tocopherol$ did not exert any appreciable antioxidant effect on the extracted oil while BHA demonstrated some effect. Ascorbyl palmitate with citric acid and especially TBHQ exerted a considerable effect. The storage stability of the samples fried with the oil fortified with TBHQ was as good as that of the samples prepared with the palm oil. The stability of the samples improved as the palm oil content In the frying oil increased. The stability of the samples fried with the blended oil containing 70f) palm oil was comparable to that of the samples prepared with the pure palm oil

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.247-254
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• 1989

In deep-fat frying, the fats and oils are used over and over again, and moisture and air are mixed in to the hot oil. Many reports related to these fats and oils have been established that thermal and oxidative decomposition products and polymers formed under the conditions of deep fat frying are harmful to health. This work was carried out with 3 domestic frying oils and 6 used oils commercially, and that there were difficulties in finding a good definition between fresh oil and used oil with adding unheated oil. As starting materials, commercially used soybean oil and rapeseed oil already passed over induction period in the lipids oxidation standard. From the qualitative point of view, they were inferior to domestic frying oils. Free fatty acid and peroxide value of heated oils were increased gradually by the time pass whereas iodine value were decreased. After adding unheated oil to the heated oil, these values were restored to that of initial levels. On the other hand, content of polar components in the heated oil were directly related to the heating time. This result showed that polar compounds may be a clear indicator of used oils. Fatty acid composition in the used oils, unsaturated fatty acids such as linoleic and linolenic acid decreased while saturated fatty acid content increased with heating.

• Korean journal of food and cookery science
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• v.15 no.3
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• pp.264-271
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• 1999

This study was conducted to know the storage stability of Yackwa, a traditional Korean fried cookie, prepared by two different cooking methods; deep fat frying at 160$^{\circ}C$ for 8 min (DFF), and preheating Yackwa dough and then deep fat frying at 180$^{\circ}C$ for 2 min (MW/DFF). Soybean oil (SBO), hydrogenated soybean oil (HSBO) or hydrogenated palm oil (HPO) were used for frying Yackwa. Compared to Yackwa prepared by DFF, all MW/DFF Yackwa samples had low fat content and high moisture content. MW/DFF saved frying time 6 min compared with DFF. Non-hydrogenated soybean oil for frying fats was replaced with hydrogenated types of soybean oil and palm oil to improve the storage stability of Yackwa. To investigate the oxidation stability of Yackwa during the accelerated storage for 15 days at 60$^{\circ}C$, acid value, anisidine value, peroxide value and oxidation value of Yackwas were measured. Acid values of Yackwa made by MW/DFF were higher than those made by DFF through the whole storage periods, regardless of frying fats. Peroxide and anisidine values of Yackwa coated with syrup were much lower than those without syrup. MW/DFF cooking method, using hydrogenated soybean oil or hydrogenated palm oil for frying, showed lowering effects on peroxide value as well as anisidine value, resulting in improved oxidation stability of Yackwa during the storage. In sensory evaluation, the acceptability of MW/DFF Yackwa was higher than those of the commerical products. Yackwa prepared by MW/DFF cooking method using hydrogenated palm oil, showed the highest acceptability in color, taste and texture among the samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.834-841
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• 2020

Laver Pyropia sp. is the most exported seafood in Korea and is one of the most consumed edible seaweeds. The export of laver has been centered on seasoned laver products; of note, laver snack products coupled with rice papers or glutinous rice paste are becoming more popular in Western countries. These laver snacks are manufactured using a deep frying process. Therefore, the frying conditions affect the physicochemical and sensory characteristics of fried laver snacks. In this study, we optimized the deep-frying conditions for laver snacks with gelatinized rice dough using a response surface methodology. The frying temperature (X1, 190-220℃) and frying time (X2, 10-30 sec) were selected as independent variables; the dependent variables were the overall acceptance (Y1, points), hardness (Y2, N), and oil content (Y3, %). The optimal values of the frying temperature (X1) and time (X2) as per the overall acceptance (Y1) were 208℃ and 23.1 sec, respectively. The predicted overall acceptance (Y1=8.0 points), hardness (Y2=98.74N), and oil content (Y3=27.69%), were similar to the experimental values under the optimal conditions. Overall, the acceptance was inversely proportional to hardness; the decrease in hardness caused an increase in the crispiness of the laver snacks.

• Resources Recycling
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• v.19 no.6
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• pp.36-42
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• 2010

Researches on resources recycling in the field of construction have made an extensive progress such as recycled aggregate of waste concrete and recycling of asphalt. On the other hand, there are almost never researches on pavement method with used waste frying oil. In South Korea, 0.2 million ton used waste frying oil is discharged every year. It is guessed that about 0.1 million ton used waste frying oil can be collected. If used waste frying oil is recycled, it is expected that disuse cost will be reduced and water pollution of rivers will be prevented. Therefore, the purpose of the study was to evaluate on mechanical features (strength, water resistance, chemical resistance, abrasion resistance, freezing and thawing resistance and permeable coefficient) whether dense graded permeable concrete mixing silica sand with flexible alkyd resin manufactured by making ester reaction with collected used waste frying oil to make alkyd resin could be applied to road pavement for non-roadway. The results of the study were as follows. In flexural strength, it had 1.6 times as much as road design standard 4.5MPa. In water resistance, chemistry resistance and freezing and thawing resistance, they had lack of strength in early age. As age went by, they didn't have large changes. And curing temperature had phenomenon of increase in strength at rather low temperature than high temperature by glass transition temperature of resin. Therefore, considering workability, strength and durability when it was applied to road pavement, it was reasonable that the mixing ratio of flexible alkyd resin was 10~15% in comparison with silica sand weight.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.472-477
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• 2012

As people are being exposed to many types of fast food, rancid oil is a factor affecting public health. Monitoring of rancidity in frying oils needs to be done adequately. The chemical methods that are currently used require long periods of time and expertise. The development of a device that quickly and easily measures rancidity would be helpful to manage rancidity in frying oils adequately. Due to the fact that carbon nanotube (CNT) is sensitive to acid value, we used CNT as a sensing material for detecting oil rancidity. Polyethylenimine (PEI) was coated on CNT for stable measurements. Experiments were conducted at $100^{\circ}C$ after samples were cooled from $180^{\circ}C$. The results showed a strong correlation between acid values and resistances using CNT sensors. As the acid value of oils increased, the resistance of CNT sensors increased. Development of sensors using CNT may make it possible to determine the rancidity of frying oils in real-time and on site.