• KSBB Journal
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• v.30 no.4
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• pp.155-160
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• 2015

The present study was to investigate the antioxidant activity in ethanol and water extracts of root and stem of Sargassum coreanum. Antioxidant activities were evaluated by total polyphenol contents, DPPH radical scavenging activity, chelating effect, reducing power, and rancimat method. Total polyphenol contents of ethanol and water extracts were 32.79 mg/g and 15.55 mg/g, respectively. Ethanol extract showed higher DPPH radical scavenging activity than water extract and similar activity to BHT. Reducing power of extracts was increased in a concentration-dependent manner and ethanol extract had more reducing power than water extract. Ethanol and water extracts have little chelating effect at all concentrations. Antioxidant index (AI) of ethanol extract measured by Rancimat was higher than that of water extract, but their AI was lower than that of BHT. These results indicate that ethanol extract of S. coreanum root and stem has more potent antioxidant activity than water extract through DPPH radical scavenging and reducing power, and could potentially be used as a good source of natural antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1767-1775
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• 2013

The purpose of this study is to investigate the total polyphenol and antioxidant activities of radish buds (Raphanus sativus L.) based on sprouting periods and extraction solvents in order to present basic data that are needed for using the radish buds as functional food material. The antioxidant activities were assessed by using various antioxidant models (DPPH, TBARS, Rancimat method, POV). The total polyphenol contents according to the extraction solvents were 84.11 and 296.51 mg/g, and the ethanol extract on day 4 of showed the highest value as 296.51 mg/g. As for DPPH radical-scavenging activity, on the day 4 of sprouting, water extracts indicated the highest scavenging activity by 86.67%, and the acetone extracts indicated a rather low scavenging activity as 77.23%. As for TBARS measurement of the radish bud extracts on day 4 of sprouting the extract of 70% ethanol was highest (71.48%). On day 8 of sprouting the TBARS value was increased and the methanol extract was highest (78.99%). As for the oxidative induction period on day 4 of sprouting in Rancimat measurement, the methanol extract was highest (6.07 hours) on day 4 and the antioxidant index was 1.16. On day 12 of sprouting, the general oxidative induction period tended to be reduced to 5.25 to 5.91 hours. In the peroxide value measurement on day 4 of sprouting and beginning of the storage, the extracts showed no difference between 3.02 meq/kg oil and 4.12 meq/kg oil, and on the day 60 of storage, the water extract (43.83 meq/kg oil) and the methanol extract (45.42 meq/kg oil) were lowest with higher antioxidant effect. In conclusion, the radish bud extract with higher total polyphenol contents and antioxidant activities may serve as functional material for food additives, such as natural antioxidants and food preserving agents.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.303-307
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• 2003

Some Compositae plants are known to contain biologically active substances that are allelopathic to weeds species as well as antioxidant to foods. Aqueous extracts from leaves of 3 plant species, Cirsium japonica, Kalimeris yomena, and Lactuca saliva, were bioassayed against alfalfa (Medicago saliva) to determine their allelopathic effects. The extracts applied on filter paper in bioassay significantly inhibited root growth of alfalfa. Extracts of 20 g dry tissue $\textrm{L}^{-1}$ from Lactuca sativa showed the most inhibitory effect on alfalfa seedling growth and followed by Cirsium japonica and Kalimeris yomena. Oxidative stability by Rancimat method and antioxidant activity by TBA method for the ground samples were the greatest in Lactuca sativa although were less than that of a commonly used antioxidant, 1% ascorbic acid. Antioxidant activity of methanol extracts on storing meat was stably kept for 28days and was excellent compared to control. These results suggest that three Compositae plants have potent allelopathic and antioxidant effects, and that their activities differ, depending on plant species.

• Food Science and Preservation
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• v.4 no.3
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• pp.317-321
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• 1997

The mineral components of the Gastrodia elata Blum were determined by inductively coupled plasma-atomic emission spectrophtometry. The mineral component contents of the Gastrodia elata Blum were greater in the order of Fe < Na < Mg < Ca < P < K. The antioxidative effects of the Gastrodia elata Blum extracts on refined perilla oil were investigated by the rancimat method, peroxide value and TBA value. The antioxidative effects of Gastrodia elata Blum added to the refined perilla oil was increased with dose-dependent fashion in concentration of Gastrodia elata Blum extracts. The peroxide value and TBA value for their antioxidation stability were also lower than that of control. Antioxidation stability was increased in a dose-dependent manner.

• Journal of the Korean Home Economics Association
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• v.29 no.4
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• pp.37-43
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• 1991

Oxidative stability of crude wheat germ oil (WGO) was determined by the active oxygen method(Rancimat, hrs at 98$^{\circ}C$). The induction time of crude WGO was 7.6hrs as compared to 23.7hrs of crude soybean oil. However, the induction time of WGO could be extended by 2-3 times with 300ppm of mixed tocopherols and 200ppm of organic acids. The antioxidant effect of organic acids increased in the order of L-ascorbic acid > tartaric acid > citric acid > malic acid. Especially, the induction time of WGO could be extended by ca. 38hrs with 500ppm of L-ascorbic acid. This antioxiative effect of 500ppm L-ascorbic acid with mixed tocopherol(100, 200, 300 or 500ppm). It seems that the synergistic effect of L-ascorbic acid was due to the high content of tocopherols(0.4%) in WGO.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.452-459
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• 2008

The purpose of this study was to investigate the antioxidative effects of Sea tangle powder(STP) solvent extracts as well as Maejakgwa made with STP. The STP solvent extracts were added to soybean oil at a quantity of 0.05%. The solvents used for extraction were methanol, ethanol, ethyl acetate, and petroleum ether. Soybean oil without added STP was used as a negative control, and soybean oil samples containing 0.02% butylated hydroxy toluene(BHT) and $\alpha$-tocopherol were used as positive control, respectively. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation levels of these samples were determined by measuring their acid values, peroxide values, and thiobarbituric acid(TBA) values. The soybean oil samples containing the STP extracts had lower oxidation levels than both the negative control and $\alpha$-tocopherol positive control, and the sample containing the 0.05% methanol extracts had the lowest oxidation. According to the Rancimat method, the methanol extract(320 min) and ethanol extract(316 min) demonstrated longer induction periods as, compared to the control(253 min), $\alpha$-tocopherol(255 min), and BHT(309 min) samples. For the Maejakgwa, acid values increased over the storage period, however, the samples made with STP had lower values than the control group. Peroxide values increased rapidly for 30 days and then decreased. The TBA values of the Maejakgwa samples made with 3% and 9% STP were lower than those of the 15% STP sample and the control. In conclusion, the oxidative stability of soybean oil containing solvent extracts of STP and Maejakgwa made with STP were increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.9
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• pp.1314-1319
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• 2005

The purpose of this study was to investigate the antioxidative effects of Lycii fructus powder (LFP) solvent extracts and Maejakgwa made with LFP. The solvent extracts of LFP were added to soybean oil in the quantity of $0.05\%$. The solvents used were methanol, ethanol, ethyl acetate and petroleum ether. Soybean oil without the addition of LFP was used as a negative control. Soybean oil with $0.02\%$ butylated hydroxytolune (BHT) and $\alpha$-tocopherol were used as positive controls. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation level of these samples was determined by measuring the acid value, peroxide value and thiobarbituric acid (TBA) value. The oxidation level of solvent extracts of $0.05\%$ LFP was lower than both the negative control and $\alpha$-tocopherol. Especially, methanol extract of $0.05\%$ LFP was the lowest. The methanol extract (320 min) and ethanol extract (316 min) demonstrated longer induction periods, compared to the control (253 min), $\alpha$- tocopherol (255 min) and BHT (309 min) by Rancimat method. Acid value of Maejakgwa was increased during the storage time, but it was lower in Maejakgwa made with LFP than in the control group. Peroxide value was increased rapidly for 30 days and then decreased. TBA value was lower in Maejakgwa made with 3, 6, $9\%$ LFP than in those made with $15\%$ LFP and the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1571-1579
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• 2009

Antioxidant activities of ethanol and water extracts from Orostachys japonicus leaf, stem, and root were determined by rancimat method, DPPH radical scavenging effect, chelating effect, and reducing power analysis. The highest total phenolic compound (TPC) as 14.6 mg/g of dry sample and the strongest antioxidant activity in rancimat method (value of AI 1.98), DPPH radical scavenging effect (96% in 4 mg/mL), and reducing power (1.50 in 4 mg/mL) were observed in ethanol extracts from Orostachys japonicus leaf. Heat and pH stabilities on antioxidant activity of Orostachys japonicus leaf extract were studied through TPC and DPPH radical scavenging effect. As a result, the extracts from Orostachys japonicus leaf showed high stability. These results suggest that extracts from Orostachys japonicus leaf can be potentially used as proper natural antioxidant in the food industry.

• Korean Journal of Medicinal Crop Science
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• v.15 no.3
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• pp.203-209
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• 2007

In order to promote utilization of the Yangha (Zinger mioga Rosc.) as functional food and natural spices, and 95.93%, from the dried one 7.63%, and from powder 9.81%, respectively. Crude protein content from the Yangha powder was 11.21%, and contents of crude fat, crude ash and crude fiber were 2.44%,10.78%, and 14.47%, respectively. Most of compositions from Yangha powder were higher than those from raw and the dried one, except fer water content. Antioxidative effect was investigated through Rancimat and DPPH methods. Oxidative stability of Yangha powder was the highest of4.21Al. Furthermore, the free radical scavenging activity of Yangha powder (76.61%) was higher than that of raw (49.35%) or the dried one (61.78%). Volatile flavor compounds of Yangha was extracted by steam distillation and extraction method. The extracts were analyzed and identified by gas chromatography and GC-MS spectrometry. One hundred twenty two volatile flavor components were identified, and the major component was terpene compounds including ${\alpha}$-pinene, ${\beta}$-pinene, ${\beta}$-phellandrene, 1,4-terpineol, and ${\beta}$-terpinene.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.201-208
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• 2007

Functional oils (FOs) were produced from commercial diacylglycerol oil and red yeast rice extracts from 80% ethanol for 1 hr in a shaking water bath at $35^{\circ}C$ and 175 rpm. FOs contained (A) 600, (B) 1200, (C) 1800, and (D) 2280 ppm of red yeast-rice extracts, respectively. The Hunter a value and b value were risen whereas L value was reduced along with the increase of extract concentration. Content of monacolin K and total phenolic compounds in FOs significantly increased according to the increase of extract concentration. The oxidation stability of FOs was observed by Rancimat at $98^{\circ}C$. Induction time decreased according to the increase of extract concentration. The major volatile compounds of FOs were compared using the electronic nose (EN) system and solid phase microextraction (SPME) method combined with gas chromatograph/mass spectrometry (GC/MS). EN was composed of 12 different metal oxide sensors. Sensitivities (Rgas/Rair) of sensors from EN were analyzed by principal component analysis (PCA), whose proportion was 99.66%. For qualitative or quantitative analysis of volatile compounds by SPME-GC/MS, the divinylbenzene/carboxene/polydimethyl-siloxane fiber and sampling temperature of $50^{\circ}C$ were applied.