• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.61-65
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• 1990

Comparison of induction times among the Rancimat Method, the Oven Test and the Weight Method were investigated, and the oxidation stability of perilla oil was determinated by the Rancimat Method. The induction times determinated by three methods using perilla oil show a good correlation. And the temperature dependence of the induction times of perilla oil was as follows. $t_p=e^{-0.0815T+9.183}$. The antioxidant effect of Tocopherols on the oxidation of perilla oil was not observed, and the antioxidant effect of the organic acids was increased in the order of Ascorbic acid>Ascorbyl stearate>Malic acid>Tartaric acid>Citric acid. The synergistic effect of Ascorbic acid (500 ppm)and Tocopherols was not observed below 200ppm of Tocopherols, but became larger with increasing Tocopherols level over 200ppm.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1751-1752
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• 2010

• Korean Journal of Plant Resources
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• v.17 no.1
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• pp.14-19
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• 2004

Aerial parts of Compositae plants were harvested from pastures and crop fields of Sunchon area at vegetative stage to determine their antioxidant activity. Among 13 species, three species Taraxacum officinate, Breea segeta, and Artemisia princeps were selected as potent plant materials. Through measurement by Rancimat and TBARS method, antioxidative effect was the greatest in Taraxacum officinate among plant species. Antioxidative index (AI) investigated by Rancimat showed Siegesbeckia glabrescensi was 1.51 while commonly-used antioxidants, BHT and ascorbic acid were 3.86 and 2.43, respectively. The highest TBARS value was also obtained from Taraxacum officinate(0.18) at 4 weeks after storage, indicating the plant had the strongest antioxidant activity during long time. Even though TBARS value (0.18) in Taraxacum officinate sample showed lower in all plants than two synthetic antioxidants(0.05-0.09), antioxidant activities of the plants were much higher than that of a control (1.01). The results suggest that the plants have antioxidant potential as an alternative natural antioxidant based on natural plant resources.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.107.1-112
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• 1992

Free-, soluble- and insoluble phenolic acids were extracted from defatted Galla Rhois. The extracts were then dissolved in equal amounts of an soybean oil, and POV (peroxide value) of the resulting substrates, portion of the soybean oil (control) and 0.02% BHT were measured by AOM (active oxygen method) test at 97.8$^{\circ}C$ for 40 hours through Rancimat method. Induction period of control, BHT, free phenolic acids, soluble phenolic acids and insoluble phenolic acids by the Rancimat method were 4.8, 10.5, 23.9 and 30.5hr. The phenolic acids separated and tentati-vely identified by gas chromatography were catechol, gallic acid, vanillin, protocatechuic acid, syri-ngic acid, ferulic acid.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.77-82
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• 1996

Antioxidative activity of the extract from Caesalpinia sappan L. by various solvent was compared with several commercial antioxidants, using the Rancimat method. AI (antioxidative index; induction period of oil containing extract/induction period of control oil) of all extracts were higher than commercial antioxidants, such as BHA, ${\delta}-tocopherol$ and ascorbic acid. The ethanol extract was fractionated by liquid liquid extraction. Ethyl acetate fraction showed higher AI than the whole crude extract. When comparing POV and TBA value of palm oil and lard containing different level of each fraction, the oxidative stability of ethyl acetate fraction at 200 ppm level on palm oil and lard were similar to that of BHT at 200 ppm level, and better than BHA, ${\delta}-tocopherol$ and control.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1355-1364
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• 1998

This study was planned to investigate the effect of 40 plant ethanolic extracts on antioxidant activities in vitro. The total phenolics, $\beta$-carotene, $\alpha$-tocopherol and selenium contents were also determined . Antioxidant activities fo the ethanolic extracts(0.02%, w/w) in the soybean oil were measured both by determining the peroxide value (POV) during 35 days of storage at 4$0^{\circ}C$ in a forced draft air-incubator and by determining changes in conductivity at 11$0^{\circ}C$(Rancimat method.). Soybean oil without any additives was used as a control and that treated with 0.02% BHT was used as a positive control. Based on the POV determination, green tea extract was found to be the most effective in stabilizing soybean oil, then followed by long tea, which both of them showed higher antioxidant activities compared to the BHT treatment. The antioxidant activities of them showed higher antioxidant activities compared to the BHT treatment. the antioxidant activities of coffee, cinnamomi cortex, acanthopanacis cortex, black tea, orange peel , instant coffee, peony and crni fructus extracts were stronger compared to the control .By the Rancimat method, green tea leaf and oolong tea leaf, foxglove, acanthopanacis cortex and peony extracts. Compared to other extracts, green tea leaf, black tea leaf, foxglove, acanthopanacis cortex and peony extracts had stronger antioxidative effects in both the POV and Rancimat methods used in this study. ethanolic extracts which showed the stronger antioxidative effect also has the higher contents of total phenolics, $\beta$-carotene, and/or $\alpha$-tocopherol. The antioxidative effect of ethanolic extracts was found to be due to the combined effect of various antioxidants.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.622-626
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• 1994

Propolis was extracted by several organic solvents, and the antioxidative effect of the extracts on palm oil and lard was tested with the extract solely or combined with some synergists, using the Rancimat Method. The extraction yields of propolis by each solvent were 68.1% (75% ethanol), 75.5% (99% ethanol), 67.4% (methanol;, 86.7% (chloroform), 72.6% (ethyl acetate) and 65.6% (butanol). AI (Antioxidative Index; induction p-eriod of oil containing antioxidant/induction period of natural oil) of the methanol extract was highest, and more effective on lard than palm oil. The ethyl acetate fraction of 75% ethanol extract showed higher antioxidative effect than 75% ethanol extract, and obtained the highest antioxidative effect on palm oil with ascorbic acid as synergist and lard with ${\dalta}-toocopherol$.

• 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.34 no.5
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• pp.893-897
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• 2002

The chloroform layer from 75% ethanol extract of Dalbergia odorifera T.CHEN showed strong antioxidative activity on lard and palm oil as tested by Rancimat method. Antioxidative active compound isolated and identified by silica gel column chromatography, thin layer chromatography, mass spectrophotometer, $^1H-NMR$ and $^{13}C-NMR$ was identified as mucronulatol (3(R&S)-3,7-Dihydroxy-2',4-dimethoxyisoflavan). Results of Rancimat method revealed the induction period of Mucronulatol increased longer than those of synthetic antioxidant, BHA and BHT, at the same concentration. Mucronulatol combined with ${\delta}-tocopherol(200ppm)$, and with ascorbic acid (200 ppm) and citric acid (200 ppm) on lard and palm oil, respectively, showed strong synergistic effects.

• YAKHAK HOEJI
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• v.47 no.4
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• pp.212-217
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• 2003

We have carried out the antioxidative activity of nuts species for the development of antioxidant from natural products. From our previous report, EtOAc and n-BuOH extracts of acorn hull and chestnut hull were found to have a strong antioxidative activity in various antioxidant experiment. In the continuous study, we isolated several compounds from EtOAc and n-BuOH extracts of acorn hull and chestnut hull by fractionation using column chromatography. The structures of isolated compounds were identified as catechin, naringenin and ellagic acid on the basis of their spectroscopic properties and by comparison of their physical and spectra data with published value. Antioxidative activities of catechin, naringenin and ellagic acid were measured by DPPH, ferric-thiocyanate and Rancimat method.