• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.177-180
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• 2007

Tocotrienols (T3) are minor plant constituents found abundantly in rice bran, which provide a significant source of vitamin E in animal feeds. T3 was reported to have an intrinsic hypocholesterolemic effect by inhibiting HMG-Co A reductase. It has similar antioxidative properties as tocopherols in food and biological system due to their similar chemical structures. However, the antioxidant activity and mechanism of T3 to scavenge free radicals and to inhibit the peroxidation of linoleic acid are less understood. The purpose of this study was to investigate the scavenging effect of T3 on free radicals and its inhibition of peroxide formation. Free radical scavenging activity was monitored by the DPPH (1,1-diphenyl-2-picrylhydrazyl) method whereas inhibition of linoleic acid peroxidation was evaluated using the thiocyanate method. Thiobarbituric acid (TBA) test was used to determine malonaldehyde formation from linoleic acid peroxidation. Free radical scavenging activity increased with increasing concentration levels of T3. T3 exhibited 38.2, 78.6, 92.7 and 96.2% radical scavenging activity at concentrations of 2, 8, 32 and 128 ppm, respectively. At 128 ppm, it was highly effective in inhibiting linoleic acid peroxidation. The activity of T3 evaluated by the thiocyanate method showed low absorbance values indicating a high level of antioxidant activity. All treatments showed similar trends in antioxidant activity when evaluated by both the thiocyanate method and TBA test.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.1-8
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• 2008

It is well known that many antimicrobial proteins in saliva interact with each other. The purpose of the present study was to investigate the interactions of lysozyme with peroxidase in the aspects of enzymatic activity in vitro. The interactions of lysozyme with peroxidase were examined by incubating hen egg-white lysozyme(HEWL) with bovine lactoperoxidase(bLP). The influence of peroxidase system on lysozyme was examined by subsequent addition of potassium thiocyanate and hydrogen peroxide. Lysozyme activity was determined by turbidity measurement of a Micrococcus lysodeikticus substrate suspension. Peroxidase activity was determined with an NbsSCN assay. The Wilcoxon signed rank test was used to analyze the changes of enzymatic activities compared with their controls. bLP at physiological concentrations enhanced the enzymatic activity of HEWL(P < 0.05) and its effect was dependent on the concentration of peroxidase. However, HEWL did not affect the enzymatic activity of bLP. Thiocyanate did not affect the enzymatic activity of HEWL, either. The addition of potassium thiocyanate and hydrogen peroxide did not lead to additional enhancement of the enzymatic activity of HEWL. The changes of hydrogen peroxide concentration in the peroxidase system did not affect the enzymatic activity of HEWL. Collectively, despite an in vitro nature of our study, the results of the present study provide valuable information on the interactions of lysozyme and peroxidase in the aspects of enzymatic activity in oral health care products and possibly in the oral cavity.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.31-36
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• 1992

The antioxidative substances in black sesame and white sesame seed were investigated. The thiocyanate test indicated the presence of antioxidative substances in the extracts of black sesame seed as well as white sesame seed. The activity of white sesame seed was more strong than that of black sesame seed. The active components were discussed after purified using silica gel adsorption chromatography, Sephadex LH-20 chromatography, $C_{18}$ column chromatography, successively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.726-731
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• 2001

To enhance the utilization of chestnut husk discarded in the processing company antioxidative activities and compounds were investigated. Antioxidative activities of solvent fractions from chestnut husk were examined by benzoic acid hydroxylation method ferric thiocyanate method and DPPH test. Ethyl acetate fraction showed strong antioxidative activities comparable to BHA. Active compounds were isolated and purified from ethyl acetate fraction by Sephadex LH-20 column chromatography and preparative HPLC. A major active compound gallic acid was identified by $^{1}$H and $^{13}$ C-NMR. The phenolic acid contents was analyzed by GC and ellagic acid (172.22 mg%) and gallic acid (107.39 mg%) were major phenolic acid of chestnut husk.

• Journal of the Mineralogical Society of Korea
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• v.27 no.2
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• pp.73-83
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• 2014

In order to investigate selective phase transformations and to determine the maximum Au leaching factors from microwave treated Au-bearing complex sulfides, a microscope, SEM-EDS analysis, and thiocyanate leaching tests were performed. When the Au-bearing complex sulfides were exposed to microwave heating, increasing the microwave exposure time increased temperature and decreased weight. Arsenopyrite was first selectively transformed to hematite, which formed a concentric rim structure. In this hematite, oxygen and carbon was detected and always showed high iron content and low arsenic content due to arcing and oxidation from microwave heating. The results of the leaching test using microwave treated sample showed that the maximum Au leaching parameters was reached with 0.5 g concentration thiocyanate, 2.0 M hydrochloric acid, 0.3 M copper sulfate and leaching temperature at$60^{\circ}C$. Under the maximum Au leaching conditions, 59% to 96.69% of Au was leached from the microwave treated samples, whereas only 24.53% to 92% of the Au was leached from the untreated samples.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.1
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• pp.1-8
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• 2004

One of the most frequently used method for measurement of the degree of sizing (viz., hydrophobicity) is the Stockigt test. However, the Stockigt test was influenced by various factors such as dropping height, dropping amount, dropping speed and viewing angle. The resultant data of the sizing degree on the same specimen also varied according to different testers. Thus, the Stockigt test should be modified to be regarded as a highly reliable and reproducible standard method. For modifying the Stockigt test, it was required to quantify red coloration by reaction between 1％ ferric chloride and 2％ ammonium thiocyante during Stockigt testing. The cameras capturing the serial images during the red coloration process were the CMOS (Complementary Metal Oxide Semiconductor)-type and CCD (Charge Coupled Device)-type cameras. For measurement based on KS M 7025, the CCD-type camera must be used due to its high resolution, and on the other hand, for measurement based on Tappi Useful Method 429, the CMOS-type camera may be used owing to its low resolution. It was needed to covert the RGB values of a droplet image into HSV(Hue, Saturation, and Value) values because the human eyes are much closer to HSV than RGB. Among HSV values, the Hue value was accepted as the most reliable index consistent with the red coloration process by excluding the surrounding conditions such as light, tester's movement etc.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.338-342
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• 2017

The antioxidant activities of sesame cake extracts prepared using ethanol and hot water were evaluated. Seventy percent-ethanol extracts yielded the highest total phenolic (96.56 mg/g extract) and flavonoid (8.35 mg/g extract) contents. In the ${\beta}$-carotene bleaching and ferric thiocyanate test, 30%-, 50%-, and 70%-ethanol extracts exhibited higher antioxidant activity than that exhibited by 90%-ethanol extracts. However, 90%-ethanol extracts showed greater antioxidant activities in phenyl-2-picryl-hydrazyl free radical scavenging test and thiobarbituric acid test using corn oil. The antioxidant activities of sesame cake extracts did not correlate with the total phenolic and flavonoid contents; however, the results suggest that oxidative stability may be improved by sesame cake extracts.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.710-714
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• 2007

Ligularia fischeri (LF) has been used to treat jaundice, scarlet-fever, rheumatoidal arthritis, and hepatic diseases. This study was carried out to determine the antioxidant activity of the extract from the leaves of LF by using various established in vitro systems with ${\alpha}$-tocopherol as positive control. The results showed that the ethanol extract of LF (0.05-0.5 mg/mL) displayed a strong free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl, ${O_2}^{{\cdot}-}$, and $H_2O_2$ radicals. It was observed that LF extract (1 mg/mL) significantly decreased the levels of malondialdehyde (MDA) to 69 and 89% of control, measured by ferric thiocyanate (FTC) and thiobarbituric acid (TBA) test, respectively. LF extract (0.5-2 mg/mL) was also found to inhibit significantly the amount of malondialdehyde formed from liver homogenate to 69-56% of control. Similarly, in the high $Fe^{2+}/ascorbate$ induction system LF extract (1-2 mg/mL) inhibited carbonyl formation measured by 2,4-dinitrophenylhydrazine reaction to 89-79% of control. Like antioxidant activity, the reducing power of LF extract was excellent at concentration of 0.5-2 mg/mL. These results indicate that LF could be used as a potential source of natural antioxidant.

• Journal of Society of Preventive Korean Medicine
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• v.13 no.1
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• pp.59-67
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• 2009

Objectives : This research aimed to evaluate the effects of Rubus coreanus $M_{IQ}$. Methods: These extracts from fresh R. coreanus $M_{IQ}$. were investigated with radical scavenging activity, the content of total phenolics, ferric thiocyanate method and flavonoid contents Results: These results revealed that the ethyl acetate extract from fresh R. coreanus $M_{IQ}$. possesses remarkable radical scavenging activity. The content of total phenolics of the ethanol extract from dried R. coreanus $M_{IQ}$. ($IC_{50}$=155.87${\pm}$8.8${\mu}$g/mL) is the highest among all of the samples. The stronger radical-scavenging activity ($IC_{50}$=77.72${\pm}$2.1${\mu}$g/mL) of ethyl acetate extract from dried R. coreanus $M_{IQ}$. should be related to its phenolic content as measured by gallic acid test. Conclusion: These results suggest that dried R. coreanus $M_{IQ}$. may act as a potential antioxidant agent.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.162-162
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• 1998

Various natural compounds act as antioxidants in protection against lipid peroxidation. Lipid peroxidation yields a variety of decomposition products which have been implicated in not only decreasing the nutritional value of food, but also in developing an off-flavor and toxic substances. As a source of safer and more effective natural antioxidants of natural origin have been widely investigated. Some Indonesian plants have evaluated for their antioxidative activity, and suggested the possible existence of various antioxygenic compounds in them. We attempted to study such antioxygenic compounds with simple method evaluation. As we are interested in the natural product compounds, we examined of several sample such as edible sea-weeds, and some edible fruits. Sea-weed, Eisenia bicyclis, one of the edible brown algae, exhibited the activity. As a traditional food additive consumed by Indonesian, Garcinia parvifolia is used as taste supplement in region West Sumatra, have been studied. Our current studies on the semi-polar fractions shows the activity by the thiocyanate method test. Another sample, Garcinia mangostana, a famous fruit with sweet taste, the part kernel have also evaluated. The acidic fraction of the extract showed antioxidative activity. Some other active components were found in the neutral and BuOH fractions.