• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.83-89
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• 1996

To evaluate the antioxidative activity of the ethanol extracts from 116 domestic medicinal plants, each extract was added to palm oil and lard in 1,000 ppm level, and the induction time was measured by Rancimat method. Almost all plant extracts tested showed more or less antioxidative activity. The extracts which had strong antioxidative activity to palm oil and lard were Caesalpinia sappan L., Paeonia japonica Miyabe et Takeda, Dendrobium moniliforme (L.) Sw and Crcumae longa L. These extracts were fractionated with chloroform, ethyl acetate, butanol and water. Ethyl acetate layer of Caesalpinia sappan L. and Paeonia japonica Miyabe et Takeda showed marked antioxidative activity, and chloroform layer of Dendrobium moniliforme (L.) Sw and Crcumae longa L. ethanol extract had stronger antioxidative activity than all the other layers.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.288-292
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• 1998

Thermooxidative stabilities of soybean oil, beef tallow and palm oil were studied during frying of steamed noodles. Steamed noodles were fried in $150^{\circ}C$ oils for 70 sec at the interval of 30 min. The frying oil was taken every 8 hrs for the analysis of peroxide value (PV) and free fatty acid (FFA) content, fatty acid composition, and tocopherol and tocotrienol content. A little change was shown in PV and FFA content in soybean oil during frying; on the other hand, rapid increase in beef tallow and palm oil was observed. Unsaturated fatty acid content was the highest in soybean oil, followed by palm oil and beef tallow. While fatty acid composition in soybean oil was not changed during frying, unsaturated fatty acid content decreased and saturated fatty acid increased in beef tallow and palm oil, which showed susceptibility to the oxidation. The ratio of linoleic acid to palmitic acid did not show difference with frying time in soybean oil: however, it decreased in other oils with a high correlation with frying time and higher decreasing rate in palm oil was observed. These suggested that soybean oil was the most stable to thermooxidation and the stability was followed by beef tallow and palm oil. Tocopherol was disappeared during frying and 87.5, 81.1, and 73.1% were remained in soybean oil after 8, 16 and 24 hour frying, respectively. Also the rate decreased in the order of ${\gamma}-,\;{\beta}-\;and\;{\alpha}-tocopherol$. However, 34.2 and 169.0 ppm tocopherol and tocotrienol which were present in control samples of beef tallow and palm oil were completely disappeared by 8 hr frying. Therefore, high thermooxidative stability of soybean oil resulted from higher residual amount of tocopherol during frying, and lower stability of palm oil than beef tallow was partly due to high degree of unsaturation.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.342-349
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• 2002

Rapeseed oil is easily oxidized due to the high contents of unsaturated fatty acid such as linoleic acid and linolenic acid. For stability of rapeseed oil oxidation, a special process is required. Two kind of simple and interesterifying mixed rapeseed oil were prepared according to add 30%, 50% and 70% of coconut oil and palm oil. Sample oils were heated at 180${\pm}$5$^{\circ}C$ for 5, 10, 15, 20, 25, 30 and 35 hours. Then the physicochemical properties such as the tendency of oxidation were investigated. The initial AV and POV of interesterifying mixed rapeseed oil were higher than those of simple mixed oil. But the tendency of oxidation were similar. While oxidation rate of similar and interesterifying mixed rapeseed oils with coconut oil and palm oil were lower about than those of rapeseed oil.

• 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

• Korean Journal of Food Science and Technology
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• v.12 no.3
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• pp.200-204
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• 1980

A series of tests ware conducted to find out whether continuous heat bleaching of the refined Malaysian plam oil stored in different conditions could reduce color of the finished oil in an actual plant situation. When the refined oil was stored in a stainless steel tank and was not abused by heat during 5 month storage period, heat bleaching followed by clay bleaching and deodorization resulted in a substantial reduction in color of the finished oil in comparison to conventional process (clay bleaching of the refined oil followed by deodorization) (2.6 vs 1.3 red in Lovibond color). However, when the refined oil was stored in a carbon steel tank and was highly abused by heat in the presence of iron picked up from the tank (6.53 ppm) during the same storage period, heat bleaching followed by clay bleaching and deodorization did not help reduce color of the finished oil in comparison to the conventional process (2.7 vs 2.8 red in Lovibond color). It was also shown that oxidation values were not good indices for heat bleachability. Heat bleaching caused slight increase in polymer content of the oil. However, trans isomers were not increased when the oil was heat bleached.

• KOREAN POULTRY JOURNAL
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• v.29 no.12 s.338
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• pp.123-131
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• 1997

• Food Industry
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• s.84
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• pp.49-51
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• 1986

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.473-478
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• 1986

In order to elucidate the patterns of natural oils and fats assimilation by microorganisms, lipases properties of yeast and bacterium strain, Torulopsis candia Y-128 and Acinetobacter calcoaceticus KB-2, which could assimilate palm oil efficiently, were investigated. T candida Y-128 attached palm oil droplets directly, and assimilated unsaturated fatty acid more easily than saturated acids liberated by the action of its lipase. Lipase of A. calcoaceticus KB-2 was extracellular and appeared quickly from the beginning of log phase of growth, whereas lipase of f candida Y-128 appealed intracellular. The lipases of two strains seem to be only enough to utilize the lipid materials for their own growth, without accumulation of lipases in the culture broth. Lipases of the strains have 1 (3-)-positional specificities on triglycerides. The patterns of palm oil assimilation showed that two strains attached droplets of lipid materials directly and split off fatty acids at 1 (3-)-position of triglycerides first, and assimilated the reaction products via fatty acids metabolic pathway.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.547-551
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• 1992

The antioxidative effects of Rhus javanica $Linn{\acute{e}}$ ethanol extract (RE) with or without some synergists were determined by measurement of POV and TBA of oil in ramyun and potato flake fried in palm oil or lard. RE with ascorbic acid and with tocopherol significantly increased the oxidative stability of ramyun. The results obtained from sensory evaluation were similar to those of POV and TBA values. RE with phosphoric acid and with ascorbic acid retarded the oxidation of potato flakes fried in palm oil or lard during storage.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.905-910
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• 2004

Effects of bamboo smoke distillates (BSD) in oxidative stability of oil during storage were investigated. BSD at 0.1, 0.5, and 1.0% was added to palm oil and lard, and peroxide, acid, and TBA values were measured during storage at $60^{\circ}C$ for 25 days. Induction periods and relative antioxidant effectiveness (RAE) for the oils were also investigated. Antioxidative effect increased with increasing concentration of BSD. Oil with 0.1% BSD had higher antioxidative effect than that with 0.02% BHT and much higher than that with 0.02% ${\alpha}-tocopherol$. Induction periods of lipid oxidation were 34.27 and 25.61 days for palm oil and lard, respectively. In oxidation reaction, palm oil was more stable during storage than lard. When 1.0% BSD was added RAEs of palm oil and lard were 233.92 and 2371.62%, respectively. Palm oil with 1.0% BSD showed higher antioxidative effect than that with 0.02% BHT, and lard showed much higher antioxidative effect than palm oil.