• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.693-699
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• 2013

This study examines the antioxidant activities and quality characteristics of fermented Codonopsis lanceolata tea according to the heating temperature and time. The browning, turbidity, reducing sugar, total polyphenol and total flavonoid contents all increased with increasing of heating temperature and time, but the pH decreased within the range of error. In particular, the total polyphenol contents of the heat treatment sample for 15 minutes at $200^{\circ}C$ are increased to about 4.5 times of 713.71mg/100ml as compared to the control group. From the results of the antioxidant activity test, as both the heating temperature and time increases, the antioxidant activity was increased for DPPH radical-scavenging activity, FRAP and reducing its power. In the case of the samples treated with heat for 15 minutes at $200^{\circ}C$ in the DPPH radical scavenging ability, it increased about twice more than the 45.17% control plot at 85.40%, and the reducing power and FRAP were increased to approximately two or three times more than the control group. According to the results for sensory test of fermented C. lanceolata tea according to heating temperature and time, the preference was confirmed as high by heat treatment due to increased temperature and time. Heat treatment process of C. lanceolata during the process is determined by the conditions required for high value-added products through the improvements of the taste and functionality of C. lanceolata.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.783-789
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• 2005

Vibriocidal GOCHUJANG was manufactured using extract of natural products and green tea. Antioxidative capacity of natural products and combination of natural products was measured with Oxidation-Reduction Potential (ORP) system value. Inhibitory ability of vibriocidal GOCHUJANG was compared with Inhibition Zone Diameter (IZD) values. Phellodendri cortex, Schizandrae fructus, Theae folium, Scutellaria baicalensis george and Acanthodanacis cortex and combination of these natural products were showed higher antioxidant capacity and inhibitory effect against V. para-haemolyticus. Two kinds of combinations, A combination was composed of Phellodendri cortex, Schizandrae fructus, Theae folium, Scutellaria baicalensis george, and B combination was consisted of Acanthodanacis cortex and A combination, were presented higher inhibition ratio with IZD values as $1.57\pm0.0051$ and $1.56\pm0.0071$, respectively. Vibriocidal GOCHUJANG was prepared based on A and B combination with their higher IZD Value as $1.76\pm0.0103$ and $1.79\pm0.0103$, respectively. When vinegar was added to A and B based GOCHUJANG, their IZD value was more higher as $2.15\pm0.0071$ and $2.44\pm0.0086$, respectively B combination based GOCHUJANG was exhibited higher inhibitory effect than A based GOCHUJANG. Combination of natural products was more important process for increasing vibriocidal effect. But addition of soybean malt or chitosan or a garlic into A or B combined GOCHUJANG, no different effect was exhibited.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.280-286
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• 2013

This study was performed to investigate the effect of types of microorganisms on the antioxidant activity of soybean yogurt by a single or mixed culture of Bacillus subtilis and Lactobacillus plantarum isolated from chunggukjang and kimchi. The fermented soybean milk by Bacillus subtilis exhibited the highest values of total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity compared to those of Lactobacillus plantarum or mixed culture of Bacillus subtilis/Lactobacillus plantarum. As the amount of tomato extract was added to the soybean milk, various antioxidant parameters, such as total polyphenol, DPPH radical scavenging activity, reducing power and nitrite scavenging activity, were linearly increased.

• Journal of Applied Biological Chemistry
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• v.61 no.4
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• pp.357-365
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• 2018

The quality of Korean doenjang, which was traditionally made for this study, was monitored for physicochemical properties, antioxidant capacity, and sensory properties at six months intervals for three years. The collected data were comprehensively analyzed using the k-means clustering via principal component analysis (PCA) to determine the optimal intake duration and sensory factors associated with acceptance. Doenjang samples were classified with every year interval based on PCA, and then the classified doenjang samples were further grouped into cluster one, two, and three based on the k-means clustering. In Cluster three, doenjang that was aged for thirty and thirty-six months, respectively, showed high total phenolic content, antioxidant capacity, superoxide dismutase like activity, and 2,2-diphenyl-1-picryl-hydrazyl radical scavenging capacity. Interestingly, along with acceptance, the levels of free amino acids and organic acids were higher in Cluster 3. The sensory factors found to be associated with acceptance included umami taste and brown color. In conclusion, this study proposes the intake of doenjang aged for thirty months based on its antioxidant activity and sensory properties although doenjang is usually ready after twelve months of aging.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.15-21
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• 2010

To investigate the effect of dietary supplementation of Acanthopanax senticosus (AS) and Eucommia ulmoides (EU) on antioxidant defense system in laying hens, a total of three hundreds sixty 20-wk old Hyline brown commercial laying hens were assigned to five dietary groups for 10-wk: (1) control diet, (2) control diet supplemented with AS at 0.5%, (3) control diet supplemented with AS at 1.0%, (4) control diet supplemented with EU at 0.5% and (5) control diet supplemented with EU at 1.0%. Total antioxidant status (TAS) in blood and antioxidant enzymes including superoxide dismutase (SOD), gluthathione -S- transferase (GST) and glutathione peroxidase (GSH-Px), and lipid peroxidation in the small intestine and liver were measured. There were no changes in body weight for 10-wk dietary treatment. TAS in blood significantly (P<0.05) increased in birds fed the diet supplemented with 1% AS and 0.5 and 1.0% EU compared with those fed control diet. Especially, dietary EU showed much higher (P<0.05) TAS compared with AS. In the antioxidant defense enzymes, GST activity of the small intestine was shown to be significantly (P<0.05) increased in birds fed the diets supplemented with 0.5 and 1.0% EU compared with those fed the control diet. In addition, intestinal SOD activity significantly (P<0.05) increased in birds fed the diets supplemented with 0.5% of AS and EU. However, we could not observe any significant dietary treatment effect of those antioxidant parameters in the liver. In conclusion, dietary supplementation of 0.5% AS and EU in a laying hen diet could be applied as a potential antioxidant source to improves bio-activity of antioxidant and economical aspect in laying hens.

• Food Science and Preservation
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• v.30 no.2
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• pp.300-310
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• 2023

This study was carried out to investigate the effect of the extraction conditions for persimmon (Diospyros kaki Thunb.) leaf tea (PLT) on its color quality and antioxidant properties. The amount of persimmon leaf (PL) powder and pH influenced the PLT's color and antioxidant capacity. As the amount of PL powder in tea increased, lightness decreased while yellowness increased. The PLT with the highest amount of PL (10 mg/mL) exhibited the highest 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity and ferric reducing antioxidant power (FRAP). In addition, the PLT with the highest PL showed the highest total polyphenol and flavonoid contents. Subsequently, PLT was prepared using 10 mg/mL PL powder under varying pH conditions. As pH increased from 4 to 7, lightness decreased while redness and yellowness increased. Antioxidant capacity was determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and FRAP assay showed that lower pH exhibited higher antioxidant capacity. The PLT extracted under the lowest pH of 4 showed higher polyphenol and flavonoid contents than that extracted under higher pH conditions. Overall, PLT extraction using a solvent with pH 4.0 showed better antioxidant activities and higher amounts of polyphenolic compounds. Simultaneously, lesser lightness, redness, and yellowness were detected in PLT extracted under pH 4 conditions. In conclusion, to acquire a better functional health benefit in terms of antioxidant capacity, preparing PLT under pH 4 conditions is suggested.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.5
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• pp.565-569
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• 1993

Antioxidative activity of browning product(BP) fractionated from fermented soybean sauce(SS) was studied during the oxidation process of linoleic acid mixture system. SSBP was a powder type product prepared from fermented soybean sauce by the fractionation through the Sephadex G-10 column and freeze drying of collected fraction. The aqueous model systems were used for the evaluation of antioxidative activity of SSBP during the oxidative reaction at $50^{\circ}C$ by the determination of peroxider and conjugated dienoic acid compounds. The linoleic acid mixture for the aqueous model systems was consisted of linoleic acid(64.6%), oleic acid(27.4%), and other acids in ethanolic phosphate buffer solution(pH 7.0). SSBP had a considerable antioxidative activity with the inhibition of formation of peroxides and conjugated dienoic acids during the autoxidation of linoleic acid mixtures in aqueous model systems. Antioxidative activity of SSBP was relatively higher than SS, however, lower than ${\alpha}-tocopherol$ and butylated hydroxyanisol. The antioxidative effect of SSBP was increased by the its concentrations from 0.05% to 0.5% in the oxidation reactions of aqueous model systems. Therefore, SSBP was considered as one of the potential natural antioxidants for the use of food products.

• Journal of Life Science
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• v.21 no.4
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• pp.596-603
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• 2011

This study was conducted to investigate traditional medicinal plants (TMP) 1 and 2, two different multi-herbal mixtures consisting of 24 herbs. Regarding the contents of flavonoid compounds, the ethanol extract (EE) of TMP2 yielded the highest content of flavonoid compounds (40.981 mg/g), followed by EE of TMP1 (28.23 mg/g), hot water extract of TMP2 (WE, 10.046 mg/g), and WE of TMP1 (6.59 mg/g). Antioxidant activities of EE and WE of TMP1 and TMP2 were measured based on DPPH radical scavenging activity. At 1 mg/ml, the highest DPPH radical scavenging activity was shown in EE of TMP2 (96%), followed by EE of TMP1 (94%). Nitric oxide (NO) production by RAW264.7 macrophage cells stimulated with lipopolysaccharide (LPS) was reduced to 82, 77, 86, and 47% by addition of $500\;{\mu}g/ml$ of EE and WE of TMP1 and TMP2, respectively. These results were not due to the cytotoxicity of the extracts. NO synthesis was increased by 2.3, 3.6, 3.0, and 1.8 fold by addition of $500\;{\mu}g/ml$ of EE and WE of TMP1 and TMP2, respectively. These results show that medicinal plants play a significant role in antioxidative activity and activation of the immune system in the pathogenesis of inflammatory diseases, and different mixtures of the medicinal plants showed different effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.250-254
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• 2007

In an attempt to find ways of improving the quality of dried Shiitake mushroom, this study compared a conveyer-type far-infrared drying method with a traditional heated air drying method. The conveyer-type far-infrared dryer was performed at air velocity of 0.6 and 0.8 m/s under drying air temperature of 60, 70 and $80^{\circ}C$, respectively. Drying characteristics, antioxidant activities and the antioxidant compounds of Shiitake mushroom dried by far-infrared dryer were investigated. Generally, drying rate with the conveyer-type far-infrared drying method was faster than that with the traditional heated air drying method. In the conveyer type far infrared drying method, drying rates were increased with increasing temperature and air velocity. The loss of antioxidant activities during the conveyer-type far-infrared drying method at 60-0.6, 60-0.8, and $70^{\circ}C-0.6m/s$ was less than the traditional drying method. However, the loss of antioxidant activities at 70-0.8, 80-0.6, and $80^{\circ}C-0.8m/s$ was higher than that of the traditional drying method. Therefore, the conveyer type far infrared drying conditions with below $70^{\circ}C$ and 0.6 m/s air velocity may produce dried Shiitake mushroom with relatively higher antioxidant activities and antioxidant compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.12
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• pp.1503-1510
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• 2007

This study was carried out to investigate antioxidant substances (phenolic compounds and brown pigment), antioxidative effect and nitrite scavenging ability (NSA) of solvent extracts (hexane: HE, methanol; ME, water: WE) from fermented soybean foods, Chungkukjang and Doenjang. The antioxidant activities were determined by the measurements of peroxide value (POV) on the linoleic acid system, electron donating ability (EDA) and superoxide dismutase (SOD)-like activity. The contents of phenolic compounds and total brown pigments in Doenjang were $28.5{\pm}0.3mg/100g$ and optical density (OD) $1.98{\pm}0.03$, respectively, whereas their contents in Chungkukjang were significantly lower with $5.8{\pm}0.3mg/100g$ and OD $0.95{\pm}0.02$. The brown pigment contents of hydrophilic extracts increased more than that of lipophilic extracts through the fermentation and ripening processes. The ME of Doenjang exhibited higher inhibitory effects against the peroxidation of a linoleic acid system than that of Chungkukjang. The EDA and NSA of MEs were higher than those of WEs. Among the MEs, Doenjang showed the highest levels of EDA and NSA. On the other hand, the SOD-like activities of WE were higher than those of ME at the same concentrations and their activities of Doenjang were significantly higher than that of Chungkukjang. In conclusion, the antioxidative effects and NSA of Doenjang was significantly higher than those of Chungkukjang. It seemed that phenolic compounds and brown pigments formed during fermentation and ripening partly affect the antioxidative activities of fermented soybean foods.