• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1041-1046
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• 2001

Solutions of fructose, glucose and sucrose were heated without catalyst at various temperature for different length of time. Changes in the formation of early caramelization product and browning intensity as well as pH of heated sugar solutions were determined. Reducing powers of caramelization products (CP) and their inhibitory effects on polyphenol oxidase (PPO) were also determined and their correlations were discussed. The early CP and browning intensity increased with temperature and time, in the order of heated fructose>sucrose>glucose solutions (p<0.005), while pH decreased. pHs of sugar solutions heated at 20$0^{\circ}C$ showed in the range of 3.32 ~ 3.50. Reducing power of CP as well as their inhibitory effect on PPO also increased with temperature and time, respectively. Among sugar solutions, reducing power showed the same trends as above at both 15$0^{\circ}C$ and 17$0^{\circ}C$ (p<0.001). However, those of heated fructose solutions were the highest in the early stage, while those of heated sucrose solutions were the highest in the final stage at 20$0^{\circ}C$. This is due to the difference in CP formed. Sucrose solution heated at 20$0^{\circ}C$ showed the highest inhibitory effect, reducing PPO activity by 34.6%. From these results, it is considered that the inhibitory effect of CP on PPO is partly related to their reducing power.

• Journal of Life Science
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• v.25 no.10
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• pp.1169-1175
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• 2015

Although many studies have described the physiological effects of bee products, such as honey, propolis, pollen, and royal jelly, the health benefits of honeycomb remain incompletely characterized. We performed a comparative study of the antioxidant properties of honey and honeycomb extracts using two different solvents (water and 95% ethanol). The results showed that the total phenolic and flavonoid content of the honeycomb extract was higher than that of the honey extract. They also demonstrated that water was more effective than ethanol in extracting total phenols. The in vitro antioxidant properties of the water honeycomb extract were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO^•) radical scavenging assays and ferrous ion chelating and reducing power assays. The antioxidant activity of the honeycomb extract exhibited was higher than that of the honey extract. The 50% effective concentrations (EC₅₀) of the honeycomb extract were 7.3±0.26 mg/ml for scavenging DPPH radicals, 6.1±0.22 mg/ml for scavenging NO^• radicals, 6.9±0.44 mg/ml for chelating ferrous ions, and 8.2±0.11 mg/ml for reducing power. A correlation analysis revealed that the total phenolics and flavonoids of the honeycomb extract were the major contributors to the radical scavenging activity, ferrous ion chelating, and reducing power. The honeycomb extract was effective in protecting biological systems against various oxidative stresses in vitro. This is the first report on the antioxidant properties of honeycomb.

• Korean Journal of Microbiology
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• v.47 no.2
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• pp.151-157
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• 2011

This study was to examine the quality characteristics and biological activities of the yogurt containing dual fermentation MFCY (Monascus-Fermented Chinese Yam) powder. Six different contents (0, 0.1, 0.3, 0.5, 1.0, and 2.0%, w/v) of MFCY powder were added to raw milk and 5% skim milk followed by fermentation with lactic acid bacteria at $37^{\circ}C$ for 12 h, and then the biological activities of the samples were investigated. Biological activities of the prepared yogurt were evaluated for acid production (pH, titratable acidity), number of viable cells, total polyphenol contents, DPPH radical scavenging activity, reducing power, angiotensin converting enzyme inhibitory effects and GABA contents. In this study, the results show that after fermentation in raw milk and 5% skim milk added with MFCY powder. The yogurt can produced pH, titratable acidity, number of viable cells, total polyphenol contents, DPPH radical scavenging activity and reducing power at 4.12-4.25 (pH), 0.94-0.97% (TA), $7.50{\times}10^9-1.14{\times}10^{10}$ CFU/ml, 161.4-329.9 (TP, mg/L), 54-94% (DPPH), and 1.13-1.53 (R.P), respectively. In addition, the showed ACE inhibitory activity and GABA contents was 67.1-87.7% and 304.6-685.4 (mg/L).

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.1098-1106
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• 2015

This study aimed to investigate antioxidant activities from 11 forest plants, and determine their total phenolics, flavonoids and proantocyanidins contents. In addition, the antioxidant activities were correlated with antioxidant compounds. Among the samples, Cornus officinalis, Castanea crenata, Lindera erythrocarpa, Carpinus laxiflora and Pourthiaea villosa showed significantly higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) ($IC_{50}=21.12{\sim}28.93{\mu}g/mL$) and 2,2'-azino-bis(3-ethylbenzothia zoline-6-sulfonic acid) (ABTS) ($IC_{50}=28.18{\sim}52.55{\mu}g/mL$) radical scavenging ability with reducing power ($IC_{50}=59.91{\sim}93.64{\mu}g/mL$) than other plants; and C. crenata, L. erythrocarpa and Rubus coreanus showed strong nitric oxide (NO) inhibition activity (${\geq}60%$). In addition, L. erythrocarpa, C. laxiflora and P. villosa showed higher oxygen radical absorbance capacity (ORAC) values (${\geq}1,100{\mu}M$ TE/g sample) than other samples. High total phenolic contents were observed in C. crenata (429.11 mg GAE/g), L. erythrocarpa (437.11 mg GAE/g), C. laxiflora (408.67 mg GAE/g) and P. villosa (404.11 mg GAE/g). The DPPH and ABTS radical scavenging activity with reducing power were significantly correlated with total phenolic contents ($R^2=0.71{\sim}0.79$), but total phenolic contents were not correlated with NO inhibition and ORAC ($R^2=0.35{\sim}0.43$). Therefore, these results suggested that C. officinalis, C. crenata, L. erythrocarpa, C. laxiflora and P. villosa are potential natural antioxidative candidate ingredients.

• Culinary science and hospitality research
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• v.16 no.4
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• pp.297-304
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• 2010

This study examines the physicochemical property and antioxidant activity of wild grape juice, and the result is as follows. Total anthocyanin and color intensity contents of wild grape juice were $17.0{\pm}0.1%$ and $33.9{\pm}1.4%$, respectively. The contents of total phenols and flavonoid in wild grape juice were $25.4{\pm}3.1$ mg/100g, $4.4{\pm}1.4$ mg/100 g, respectively. Total mineral content in wild grape juice was $28.5{\pm}8.4$ mg/l00 g and the potassium content($11.3{\pm}0.3$ mg/100 g) was the highest Electron donating abilities of wild grape juice at concentration of $1,000\;{\mu}L$/mL were $94.8{\pm}1.2%$ Reducing power of wild grape juice at concentration of $1,000\;{\mu}L$/mL was 1.134. The electron donating abilities and reducing power were increased significantly with the sample concentration in the reaction mixture increased The nitrite scavenging ability was dependent on pH of the reaction mixture and sample concentration. The nitrite scavenging ability of wild grape juice was $77.1{\pm}1.1%$ at concentration of $1,000\;{\mu}L$/mL under pH 1.2.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.69-78
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• 2010

To get basic data for the utilization of Pinkpop Borisu fruit and leaf as a raw material in functional food, antioxidative activities were investigated. The radical scavenging activity of various solvent fraction from fruit and leaf against the DPPH and ABTS radicals increased with the increasing amount of various solvent fractions and butanol fraction of leaf showed the highest DPPH radical scavenging activities. Among the various solvent fractions from fruit and leaf of Pinkpop Borisu, butanol fraction of leaf showed the strongest scavenging effect on ABTS radicals. Reducing power and ferric reducing/antioxidant power (FRAP) of the various solvent fractions from fruit and leaf increased with the increasing concentration of fractions and butanol fraction of leaf showed the highest reducing power. The butanol fraction of fruit and leaf showed strong antioxidative activity on linoleic acid system. Total phenolics contents of butanol fraction from fruit and leaf were 106.34 and 252.46 mg/g, respectively. The antioxidative activities of the butanol fraction from fruit and leaf are attributed to phenolic compounds. The present results suggest that butanol fraction of Pinkpop Borisu leaf would have the protective potential from oxidative stress induced by free radicals.

• Journal of the Korean Society of Food Culture
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• v.30 no.2
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• pp.220-226
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• 2015

This study was to conducted to investigate the antioxidative activity of 70% ethanol extracts of kiwi of three different colors (gold, green and red) by measuring DPPH, ABTS radical scavenging activity, tyrosinase inhibitory effect, metal chelating effect, reducing power, and nitrite scavenging activity. Total polyphenol contents were: gold kiwi, 3.09 mg GAE/g, green kiwi 2.71 mg GAE/g, and red kiwi 4.59 mg GAE/g, respectively. Red kiwi showed higher antioxdidant activity than gold and green kiwi. DPPH and ABTS radical scavenging activity, and nitrite scavenging activity of red kiwi exhibited 94.83, 99.57, and 97.88%, respectively, at a concentration of 20 mg/mL, which were equal to those of ascorbic acid (positive control). Metal chelating effect of red kiwi was superior to that of ascorbic acid. Therefore, the availability of red kiwi will be increased in the field of functional material for food additives and value added products.

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.521-528
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• 2016

The antioxidant activity of 70% methanol, 70% ethanol and chloroform-methanol (CM, 2:1, v/v) extracts from turmeric (Curcuma longa L.) was investigated in this study. The antioxidant potential of various extracts of turmeric was evaluated by using different antioxidant tests, namely DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, ferric reducing antioxidant power and ${\beta}$-carotene bleaching assays as well as total phenol content and total flavonoid content. All extracts exhibited abundant total phenol content, total flavonoid content and strong antioxidant activity. Particularly, higher activity was exhibited by CM extract with $46.32{\pm}0.35mgCAE/g$ and $15.58{\pm}0.39 mgQE/g$ of total phenol content and total flavonoid content. Generally, antioxidant activity of various extracts from turmeric increased in the following order: 70% methanol extract, 70% ethanol extract and CM extract, respectively. Results suggested that turmeric could be widely used as a source of antioxidant and a kind of functional material in food.

• Advances in Traditional Medicine
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• v.8 no.2
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• pp.135-145
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• 2008

The study was aimed at evaluating the antioxidant and free radical scavenging activities of ethanolic extract and its fractions of Cleome rutidosperma. The antioxidant activity, reducing power, total phenolic content, total flavonoid content, superoxide anion scavenging activity, nitric oxide anion scavenging activity, in vitro antilipid peroxidation activity and in vitro non-enzymatic hemoglobin glycosylation were studied. The results obtained in the study indicate that Cleome rutidosperma is a potential source of natural antioxidant. All the parameters were found to be concentration dependent and increased with increasing amounts of sample. Flavonoids, phenolic compound like tannins, terpenoids may be responsible for the antioxidant activity of the plant. Variation of solubility parameters in various models may be attributed to non-linearity of activity of ethanol extract fractions models. Further investigation on the isolation and identification of antioxidant component(s) in the plant may lead to chemical entities with potential for clinical use.

• ALGAE
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• v.24 no.3
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• pp.179-184
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• 2009

Methanol crude extract of the sea grass Zostera marina L. and organic solvent fractions (n-hexane, chloroform, ethyl acetate, n-butanol, and water) were screened for antioxidant activity (total phenolic contents, DPPH scavenging activity, and reducing power) and antimicrobial activity against three human skin pathogens, two bacteria and a yeast; Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Total phenolic contents and 2, 2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity were highest in the ethyl acetate fraction with 968.50 $\mu$g gallic acid equivalent per milligram of extract, and ca. 95% scavenging activity on the DPPH radicals at 10 mg $ml^{-1}$. In antimicrobial activity tests, MICs (Minimum Inhibitory Concentration) of each Zostera marina extract partitioned ranged from 1mg to 8 mg $ml^{-1}$ (extract/ 10% DMSO) against all three human skin pathogens. The MICs of the ethyl acetate and n-butanol fractions were the same with 1 mg $ml^{-1}$ against S. aureus and C. albicans. The ethyl acetate fraction of Z. marina does protect against free radicals and may be used to inhibit the growth of human skin pathogens.