• KSBB Journal
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• v.11 no.5
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• pp.572-576
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• 1996

Conditions for the culture of Pleurotus spp. mycelium using rancid frying oils were investigated. Among the six strains tested, Pleurotus ostreatus CBS 03 showed the greatest mycelial growth on fish paste and ramyon frying oil, and was used in this study. The optimum temperature and pH for mycelial growth were from 25 to $30^{\circ}C$ and pH 5.5 to 6.0, respectively. Tryptone for mycelial growth was better than any other nitrogen sources. The addition of $KH_2PO_4 and MgSO_4$ enhanced mycelial growth at 0.2 and 0.01% on fish frying oil, and at 0.1 and 0.03% on ramyon frying oil. Among the vitamins used, thiamine and nicotinic acid were the most effective ones.

• 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.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.305-309
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• 1996

The conditions for mycelial production of mushroom rising rancid oil of fried chicken were investigated. Pleurotus ostreatus Nonggi 202 which showed the greatest mycelial growth among mushrooms was chosen for the investigation. The optimum temperature and pH for mycelial growth were $25^{\circ}C$ and 5.5 to 6.5, respectively. Tryptone was better effective than any other nitrogen sources on the mycelial growth. The mycelial growth was enhanced with addition of 0.3% $KH_2PO_4$. and 0.02% $MgSO_4$, respectively. Among the vitamins, thiamine was the most effective on the mycelial growth.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.114-120
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• 1985

This study was carried out to investigate the storage stability of Yackwa (a Korean fried cake made from wheat flour, honey and 20% oil), with the variation in frying oils (soybean oil of fresh or heat-treated corn oil and rapeseed oil) and storage conditions (temperature, humidity and in dark or under fluorescent light) for 20 weeks period. In $5^{\circ}C$ storage, acid and peroxide values increased slowly, showing the peroxide value of 20 meq/kg after 13 weeks. In $40^{\circ}C$ storage, acid and peroxide values increased remarkably. The product became harder at storage humidity of 25% and softer by moistening at storage humidity of 80%. Acid and peroxide values of Yackwa from corn, rapeseed and soybean oils increased with storage period, to a different extent. The values of fluorescent groups, especially rapeseed oil group, were higher than those of control groups and the heat-treated oil groups were higher than those of fresh oil groups. Sensory scores for rancid flavor were gradually increased with the storage period in all groups. There was no significant difference with the kinds of frying oils, storage conditions and heat treatment. Correlation of sensory scores with acid values was positive throughout whole storage period, with low ${\gamma}-values$. Its correlation with peroxide values was positive up to 6th week but negative at 9th week of storage.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.255-260
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• 2002

Yukwa is a popular Korean traditional fried rice snack. The high fat content and porous structure of Yukwa cause it to rapidly become rancid, presenting difficult challenges for commercial distribution. In this study, an-tioxidant activities of green tea extracts (GTE) were evaluated in Yukwa fried in soybean oil (SBO), rice bran oil (RBO) and winterized rice bran oil (WRBO) during storage at 4$0^{\circ}C$ for 12 weeks. Lipid oxidation of Yukwa was determined by acid value (AV), peroxide value (POV), p-anisidine value(AnV), totox value and sensory evaluation. The addition of GTE to the oils reduced the increases in AV, POV, AnV, and totox. Totox increased most vapidly in Yukwa fried in SBO, fellowed by RBO>WRBO>SBO+200 ppm GTE>RBO+200 ppm GTE > WRBO + 200 ppm GTE (p<0.05). Sensory evaluation revealed that the addition of 200 ppm GTE delays rancidity in Yukwa by 7~8 weeks; providing compelling evidence that GTE is an effective antioxidant for Yukwa.

• Korean journal of food and cookery science
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• v.18 no.6
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• pp.557-561
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• 2002

The changes in some chemical and physical properties of fresh or rancid soybean oil by the treatment with sweet potato, potato, burdock, and carrot were investigated. The results of the study were as follows: The specific gravity of the soybean oil increased by heating and decreased by the addition of sweet potato, burdock and carrot into the oil. The chromaticity of soybean oil increased by heating and treatment with above vegetables having antioxidant activity. To investigate the antioxidant effects of above vegetables during heating, anisidine value (AV) and DPPH (1,1-diphenyl-2-picrylhydrazyl) electron donating ability were measured. The AV of oil decreased by heating with sweet potato in fresh or rancid oil. The DPPH value decreased by heating with sweet potato and carrot, of which the antioxidant activity were similar to that of 0.02 ∼ 0.05 mg of dl-${\alpha}$ -tocopherol.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.720-727
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• 2001

This study was carried to investigate the changes in physical and chemical properties of Yukwa during preparation with addition of antioxidants and to develop its storage condition. Antioxidants (tocopherol and Oxyfos) were used in syrup coating and the packaging materials used were PET/EVOH $(16\;{\mu}m)/PL$ : P1 and PET/EVOH $(24\;{\mu}m)/PL$ : P2 (YOP1: P1 with Oxyfos, YOP2 : P2 with Oxyfos, YTP1 : P1 with tocopherol, YTP2 : P2 with tocopherol). Color values measured for Yukwa showed that L values of YOP1, YOP2, YTP1 and YTP2 were changed little during storage while a and b values of YOP1, YOP2, YTP1 and YTP2 were slightly decreased. Hardness and chewiness in textural properties were also decreased during storage. Yukwa packed in YOPl and YOP2 maintained less than 40 in peroxide value during for 12 weeks of storage period. The major fatty acid composition of frying oil were linoleic acid (54.2%), oleic acid (23.4%), palmitic acid (11.3%), linolenic acid (6.5%) and stearic acid (4.6%). There was no difference in composition of fatty acid during storage. Sensory evaluation (Yukwa odor and rancid odor) showed very similar results with determined by electronic nose. YTP1 and YTP2 had maintained sensory characteristics of Yukwa during 10 weeks storage.