• Food Science and Preservation
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• v.21 no.3
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• pp.388-395
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• 2014

Six types of mixed cereals powder were prepared using different mixing ratios of barley, proso millet, sorghum, and adlay, and their nutritional components and functionalities were analyzed. The mixed cereals powders contained high levels of crude protein. The free amino acid and mineral contents of Sample E were the highest among all the samples. Fructose, glucose, sucrose, and maltose were detected as the four major free sugars in all the mixed cereals powders, and Sample D had the highest amount of reducing sugar among all the samples. The total polyphenol and total flavonoid contents of Sample F were significantly higher than those of the other samples. Sample C showed the highest level of DPPH radical scavenging activity and reducing power. As for the ABTS radical scavenging activity, the $IC_{50}$ of Sample D was the lowest among all the samples, but did not significantly differ from that of Sample C. Therefore, we suggest 2:2:1:1 (in Sample D) as the best mixing ratio of barley, proso millet, sorghum, and adlay to produce a mixed cereals powder with excellent nutritional value and antioxidant activities.

• Korean Journal of Poultry Science
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• v.38 no.2
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• pp.105-112
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• 2011

This study were investigated the effects of dietary supplementation of ground Kalopanax pictus leaves powder on pH, total phenol contents, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, TBARS, WHC, shear force, meat color, sensory evaluation, and fatty acid composition of chicken meat. Broiler chicks were fed diets for five weeks containing 0% Kalopanax pictus leaves powder (Control), 0.5% Kalopanax pictus leaves powder (T1), 1.0% Kalopanax pictus leaves powder (T2), and 2.0% Kalopanax pictus leaves powder (T3). The pH and TBARS were significantly decreased by the supplementation of Kalopanax pictus leaves powder compared to the control (P<0.05). The total phenol contents and DPPH radical scavenging activity were significantly increased by the supplementation of Kalopanax pictus leaves powder compared to those of the control group (P<0.05), and especially, T3 was significantly (P<0.05) more effective in improving freshness compared to other treatment groups. The WHC and shear force were not significantly different. CIE $L^*$ and $a^*$ value of treatment groups (especially T3) showed significantly higher value compare to the control, however, no difference in the CIE $b^*$ values was observed among treatment groups. In fatty acid composition, linolenic acid of chicken meat was increased by the supplementation of Kalopanax pictus leaves powder than compared to those of the non-supplementation group. In conclusion, a supplementation of Kalopanax pictus leaves powder was effective in decreasing pH and TBARS, and increasing total phenol contents and DPPH radical scavenging activity.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.300-305
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• 1998

Kinetics of termonomer emulsion polymerization during interval II (i.e, after completion of latex particle formation) were studied through pseudo-homopolymerization (PHP) method. Extended Smith-Ewart equation and equation of instantaneous polymer composition are respectively reduced to the corresponding equation for homopolymerization by defining average rate constants. Average number of radicals per particle and instantaneous polymer compositions were respectively predicted by varying termonomer composition within latex particles for systems containing no more than one growing radical per particle. Styrene-Methyl methacrylate-Acrylonitrile (SMA) system was used for model calculation.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.71-76
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• 2006

Porous polymer monolithic columns were prepared by the direct free radical copolymerization of methacrylic acid and ethylene glycol dimethacrylate within the confines of a chromatographic column in the presence of toluene-dodecanol as a porogenic solvent. The separation characteristics of the monolithic columns were tested by a homologous series of xanthine derivatives, theophylline and caffeine. The effects of the polymerization mixture composition and polymerization condition, mobile phase composition, flow rate and temperature on the retention times and separation efficiencies were investigated. The results showed that the selection of correct porogenic solvents and appropriate polymerization conditions are crucial for the preparation of the monolithic stationary phases. The separation efficiency was only extremely weakly dependent on flow rate and temperatures. Hydrogen-bonding interaction played an important role in the retention and separation. Compared with conventional particle columns, the monolithic column exhibited good stability, ease of regeneration, high separation efficiency and fast analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.366-373
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• 2015

This study was conducted to clarify the antimicrobial effect, antioxidant and tyrosinase inhibitory activities of the biological composition having the Phytolacca americana, and to enhance the natural materials utilization of foods and cosmetics. The antimicrobial activities of the different parts of P. americana were evaluated using the agar diffusion test. The antimicrobial activity of P. americana was relatively high in Malassezia furfur known as a skin fungi and Vibrio parahaemolyticus compared to Escherichia coli and Staphy-lococcus epidermidis. However, the antimicrobial activity in Vibrio parahaemolyticus did not show at all parts of P. americana. Both the DPPH radical scavenging activity and ABTS radical scavenging activity have been increased with the higher concentration of methanol extract. In particular, leaf extract of P. americana exhibited the highest activity both ABTS radical scavenging activity and DPPH radical scavenging activity. The nitrite scavenging activity was decreased when the pH was changed from pH 1.2 to pH 6.0. The highest nitrite scavenging activity was exhibited from the methanol extract of fruit, followed by root, stem, and leaf at pH 1.2. However, the nitrite scavenging activity at pH of 6.0 was not almost detected. All plant parts of P. americana showed tyrosinase inhibitory activity. The highest activity was found in the stem, and followed by root, leaf, and fruit in order. These tyrosinase inhibitory activity was progressively increased in a concentration-dependent manner. In this experiment on the methanol extracts of different organ from P. americana, we confirmed that the extract of P. americana showed potent tyrosinase inhibitory activity. Taken together, we conjectured that the P. americana had the potent biological activities, therefore this plant having various functional components could be a good material for development into source of natural food additives and cosmetics.

• Korean journal of food and cookery science
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• v.27 no.3
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• pp.39-49
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• 2011

This study was conducted to evaluate the effects of adding unrefined oil on the antioxidant activity of a tuna oil-enriched emulsion by determining DPPH radical scavenging activity, reducing power, and inhibition of low-density lipoprotein (LDL) oxidation in vitro. The emulsion consisted of tocopherol-stripped canola (18.3 g) and tuna (9.1 g) oil, one of the unrefined oils (4.6 g), such as extra virgin olive, mustard, perilla, or sesame oil, 0.5% acetic acid (64 g), and egg yolk powder (4 g). The control emulsion contained only canola (21.4 g) and tuna oil (10.6 g), as oil sources,with the same composition of the remaining ingredients. The emulsion with added unrefined oil, particularly mustard oil, showed higher radical scavenging activity and reducing power than those of the control emulsion. The radical scavenging activity and reducing power of the emulsion with added unrefined oil were higher at 1,000 ppm than at 500 ppm thus, the effect was concentration-dependent. Adding sesame or perilla oil to the tuna oil-enriched emulsion resulted in higher inhibition of LDL oxidationwhereas adding olive oil increased LDL oxidation. The results clearly showed that adding roasted mustard, sesame, or perilla oil improved the antioxidant activity of a tuna oil-enriched emulsion by increasing free radical scavenging activity, reducing power, and inhibiting LDL oxidation. The results also suggest that adding unrefined oils produces a healthier fish oil-enriched salad dressing recipe.

• Journal of the Korean Wood Science and Technology
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• v.45 no.1
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• pp.96-106
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• 2017

This study aims to identify the chemical compositions and antioxidant activities of essential oil, extracted from the leaves of Neolitsea aciculata (Blume) Koidz by the hydrodistillation method. To the end, the chemical composition of N. aciculata leaf oil was firstly analyzed through GC/MS. The major constituents of essential oil were found to be: cis-ocimene (11.00%), trans-ocimene (9.65%), elemol (9.15%), ${\beta}$-elemene (8.75%), germacrene-D (7.55%), trans-caryophyllene (5.90%), ${\gamma}$-elemene (5.40%) and ${\tau}$-muurolol (4.95%). Then, the antioxidant potential of the essential oil was evaluated by the methods of total polyphenolic content (TPC) assay, DPPH radical scavenging activity, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP). It was estimated that the total polyphenolic content of the oil was $136.7{\pm}0.13\;mg\;GAE/g$ and the efficient concentration of the oil required to scavenge 50% DPPH radicals ($EC_{50}$ value) was $639.33\;{\mu}g/m{\ell}$. Also, ABTS radical scavenging activity was identified to be concentration dependent, while the FRAP value was $31.21{\pm}0.12\;{\mu}M$ $FeSO_4{\cdot}7H_2O/g$. Such figures, as a result, suggest that the essential oil extracted from the leaves of N. aciculata has its antioxidant activity, which can serve as significant health functional benefits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1053-1062
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• 2011

Reactive oxygen species (ROS), including singlet oxygen (${O_2}^1$), superoxide anion radical ($O_2{\cdot}^-$), hydroxyl radical ($HO{\cdot}$), peroxyl radical ($ROO{\cdot}$), hydrogen peroxide ($H_2O_2$), and hypochlorous (HOCl), are generated as byproducts of normal cellular metabolism. ROS induce damage to many biological molecules, such as lipids, proteins, carbohydrates, and DNA. It is widely believed that some degenerative diseases caused by ROS can be prevented by the high intake of fruits and vegetables due to their antioxidant activities. Recently, research on natural antioxidants has become increasingly active in various fields. Several assays have been developed to measure the total antioxidant capacity of antioxidants in fruits and vegetables in vitro. These assays include those for DPPH radical scavenging activity, SOD-like activity, total polyphenol content, oxygen radical absorbance capacity, reducing power, trolox equivalent antioxidant capacity (ABTS assay), single-cell gel electrophoresis (comet assay), and a cellular antioxidant activity assay. Because different antioxidant compounds may act through different mechanisms in vitro, no single assay can fully evaluate the total antioxidant capacity of foods. Due to the complexity of the composition of foods, it is important to be able to measure antioxidant activity using biologically relevant assays. In this review, recently used assays were selected for extended discussion, including a comparison of the advantages and disadvantages of each assay and their application to fruits and vegetables.

• Journal of the Korean Society of Food Culture
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• v.30 no.3
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• pp.362-369
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• 2015

This study compared the nutritional composition and antioxidative activities of different parts (aerial part and root) of Taraxacum coreanum and Taraxacum officinale. To identify the nutrient composition of different parts of Daedelion species, nutrient contents were analyzed. Crude ash, protein, and fat contents of T. coreanum and T. officinale were higher in the aerial part compared to the root. There was no significant difference in crude ash, protein, or carbohydrate content of the aerial part depending on the Daedelion species. Aerial part contents of vitamin A, E, and C were significantly higher in T. coreanum than T. officinale. The K content of the aerial part of T. coreanum and T. officinale was highest, although there was no significant difference among Daedelion species. Contents of oxalic acid, citric acid, and acetic acid in the aerial part of T. coreanum were highest. Contents of total polyphenols, total flavonoids, and DPPH radical scavenging activity of the aerial part were significantly higher in T. coreanum than T. officinale. In conclusion, the aerial part of T. coreanum and T. officinale could be used as antioxidative functional food sources.

• Journal of the Korean Dietetic Association
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• v.19 no.4
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• pp.389-399
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• 2013

This study compared the nutritional composition and antioxidative activity of different parts of Taraxacum coreanum (aerial parts and roots) according to different drying methods (natural drying and freeze-drying). There were no significant differences in vitamin C content in roots depending on the drying methods. However, vitamin A (P<0.01), E (P<0.001) and C (P<0.001) content of aerial parts, and vitamin A (P<0.001) and E (P<0.05) content of roots were significantly higher after freeze-drying compared to natural drying. For organic acids, the oxalic acid content of the aerial parts and roots were the highest. The total polyphenol and total flavonoid content in extracts from the aerial parts (P<0.01) and roots (P<0.05) were significantly higher after freeze-drying compared to natural drying. In addition, the total polyphenol and flavonoid content, DPPH radical scavenging activity, and antioxidative index from the natural drying and freeze-drying of Taraxacum coreanum extracts were significantly higher in the aerial parts compared to the roots (P<0.05). These results suggest that the nutritional composition and antioxidative activity of Taraxacum coreanum are higher in the aerial parts compared to the roots, and higher after freeze-drying compared to natural drying. Therefore, the aerial parts of Taraxacum coreanum could be suggested as an antioxidative functional food source.