• Korean Journal of Food Science and Technology
• /
• v.22 no.3
• /
• pp.255-260
• /
• 1990

The effects of different concentrations of tocopherols on the oxidation stability of evening primrose oil (EPO) in the dark $(35{\pm}2^{\circ}C)$ were evaluated by some physicochemical characteristics such as peroxide, conjugated diene value and fatty acid composition. The results of the present study were as follows; Alpha-tocopherol at all concentrations (0.02%, 0.05%, 0.10%) showed a prooxidant effect during autoxidation of EPO. This prooxidant activity of alpha-tocopherol increased as its concentration increased rapidly. Delta-tocopherol showed antioxidant activity as its concentration increases at an early stage of storage. But the activity was fairly poor antioxidant activity and was not greater than antioxidant activity of BHT. However, the antioxidant effect of delta-tocopherol and BHT showed no apparent differences as compared with result of none.

• International Journal of Oral Biology
• /
• v.30 no.4
• /
• pp.125-130
• /
• 2005

Thrombin-induced platelet microbicidal proteins (tPMP) are antibacterial proteins released when platelets are stimulated by thrombin. It has been reported that tPMP has antibacterial activity against various bacterial species including causative agents of infective endocarditis. Most of the oral streptococci have resistance to the killing by tPMP and this fact may play an important role as a virulence factor in infective endocarditis. However, the susceptibility and resistance mechanism of oral streptococci for tPMP have not been revealed yet. In this study, the killing mechanism of tPMP for oral streptococci has been investigated. Streptococcus rattus BHT, a susceptible strain, and Streptococcus gordonii DL1, a resistant strain, have been used in this study. tPMP was isolated from platelet after stimulation with thrombin. Cell membrane depolarization was examined with 3,3'-dipropylthiodicarbocyanine iodide ($DiSC_3$), membrane potential-sensitive cyanine dye, by fluorescence spectrophotometry. The permeabilization of cell membrane by tPMP was investigated with propidium iodide (PI) by flow cytometry. tPMP susceptible S. rattus BHT showed the increase of the $DiSC_3$ fluorescence level meaning depolarization of cell membrane and increase of the uptake of PI which means permeabilization of cell membrane. However, tPMP resistant S. gordonii DLI did not show depolarization and permeabilization. These results indicate that the increasing depolarization and permeabilization of oral streptococcal cell membrane are associated with the bactericidal activity of tPMP.

• Korean journal of food and cookery science
• /
• v.24 no.1
• /
• pp.46-51
• /
• 2008

In this study, the antioxidant and antimutagenic activities of Cuscutae semen ethanol extract were evaluated. Antioxidant activity was measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the Ames test was employed to determine the inhibition effect on mutagenicity in Salmonella typhimurium TA100. The extract showed significant free radical-scavenging activity towards the DPPH radical, and at a concentration of 400 ppm, its free radical-scavenging activity was similar to that of BHT. The $IC_{50}$ value of the extract was 89 ppm, indicating good antioxidant capacity. Moreover, at 5 mg/mL, the extract presented inhibitions of approximately 98.0% and 49.2% on mutagenicity induced by 4-nitroquinoline 1-oxide and sodium azide, respectively. The total polyphenols and flavonoid contents of the extract were 20.1 mg/g and 1.9 mg/g, respectively. Therefore, this study indicates that the ethanolic extract of Cuscutae semen has excellent antioxidative and antimutagenic potential.

• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.464-469
• /
• 1996

Pleurotus ostreatus was extracted with hexane, ethanol and water to test the antioxidative activity on soybean oil. The extraction yield was the highest in the water fraction. The total sugar was higher in ethanol and water fractions, While the total phenolic substances were relatively higher in the hexane fraction. The antioxidative effects of the extracts on the oxidation of soybean oil during storage at 60 and $100^{\circ}C$ were studies. The antioxidative effects of ethanol extracts of both fruit body and mycelia of pleurotus ostreatus were higher than those of water and hexane extracts. The antioxidative effects of Pleurotus ostreatus extracts (3,000ppm) were higher than the artificial antioxidant (200ppm), BHA and BHT, during storage at 60 and $100^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.6
• /
• pp.969-972
• /
• 2000

Quality characteristics and functional properties of four kinds of propolis collected from 4 different regions were compared. Ethanol extract of propolis (EEP) showed high absorbance of UV at 208 ~ 212 nm and at 292~294 nm. Total flavonoid contents of 4 propolis were at a range of 16.30~21.87 mg/g However, no significant difference in the flavonoid content was observed among four kinds of sample. All EEP showed the high antimicrobial activities, especially against Salmonella typhimurium. Hydrogen donating activities of the EEP were high appear 65.94 to 78.67% in all samples. The EEP from Sunchon showed the highest activity of hydrogen donation among samples. All extracts had the higher nitrite-scavenging activity than 0.1% BHT. Compared to control, a significant decrease in lipid oxidation was found in all 4 extracts.

• Applied Biological Chemistry
• /
• v.45 no.3
• /
• pp.168-172
• /
• 2002

Antioxidative activities of solvent fractions obtained from Korean Rhus vernicifera, being used in food industry and as a traditional medicine, were examined by the methods of DPPH scavenging activity, inhibitory effect on autooxidation of linoleic acid, nitrite scavenging activity and the inhibitory effect on xanthine oxidase activity. Ethyl acetate fraction showed potent antioxidative activities. Three compounds were isolated from the ethyl acetate fraction by rotatory locular counter current chromatography (RLCCC), Sephadex LH-20 column chromatography and HPLC. The isolated compounds were 1,2,3-trihydroxybezene, methyl 3,4,5-trihydroxybenzoate and 3,4,5-trihydroxybenzoic acid determined by GC/MS and, $^1H$ and $^{13}C$ NMR. Among the isolated compounds, methyl 3,4,5-trihydroxybenzoate showed the strongest antioxidative activity than artificial antioxidants, BHA and BHT in various methods. However, these isolated compounds did not show cytotoxicity effects on the human cancer cell lines. Therefore, we may suggest that methyl 3,4,5-trihydroxybenzoate can be used as a food additive possessing the potent antioxidative activity.

• Journal of Ginseng Research
• /
• v.23 no.3 s.55
• /
• pp.176-181
• /
• 1999

The purpose of this study was to investigate the antioxidant activities of water soluble browning reaction products (WS-BRPs) isolated from korea red ginseng. Antioxidant activities of WS-BRPs were examined with the various systems. All three WS-BRPs (L, S-1 and S-2) were found to have an ability to donate hydrogen to DPPH. Especially, L was more effective than S-1, S-2. and, L as well as S-1 and S-2 was the strongest than BHT, BHA $(5{\times}10^{-4}M),\;{\alpha}-tocopherol\;(1.0{\times}10^{-4})$ and ascorbic acid $(5.7{\times}10^{-3}M)$ previously known as antioxidants. These WS-BRPs (L, S-1 and S-2) also showed a synergistic effect against antioxidative activities of these antioxidants. Moreover S-2 had the strongest activity of these three WS-BRPs to scavenge free radicals such as hydrogen peroxide $(H_2O_2)$.

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

• KSBB Journal
• /
• v.22 no.2
• /
• pp.78-83
• /
• 2007

In this study, we investigated the biological activity of antioxidant and antibacterial activity of Indigenous Plants, Jeju-Island., which, using methanol were extracted. The reducing activity on the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and $O^{2-}$ and OH radical scavenging potential, in search for antioxidation activities of Indigenous Plants, were sequentially screened. Among the ten plant parts, Prunella vulgaris var. aleutica Fernald. flower had the highest antioxidative activity. 80% Methanol extracts of ten indigenous plants were screened for antibacterial activity 13 fish pathogenic bacteria by agar diffusion method. Among the various 80% Methanol extracts, the Prunella vulgaris var. aleutica Fernald, Gleichenia japonica Spreng, Microlepia marginata (panzer) Christ., Perilla frutescens var. japonica Hara. showed relatively strong antibacterial activities in the order.

• Korean Journal of Agricultural Science
• /
• v.21 no.1
• /
• pp.28-36
• /
• 1994

Studies on the food-safety of pheasant and mallard, which belong to wild fowl as new meat resources. were carried out. The results were summarized as follows : 1. Food poisoning bacteria including Salmonella spp, was not detected from the inspections of small intestine, cecum, and rectum. 2. Parasite inspection tests on blood, feces, digestive organ, and thoracic organs were negative. 3. Antibiotic residues from the carcass muscle by simplified disk methods were not detected. 4. Seven different pesticide residue tests, such as DDT and BHT, on the muscle and liver were negative. 5. Four different kinds of toxic heavy metals such as Cd were much lower than the permissible concentration. Studies on the food safety tests and inspections from the pheasant and mallard were revealed that from taking this new food resources, the toxicities would be very low for the human health by the direct influences.