• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1385-1390
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• 2016

Gallic acid is a representative hydroxybenzoic acid and is found in free form in several plants and in various esterified forms as a part of hydolyzable tannins. Convenient enzymatic transformation of trihydroxylated gallic acid with polyphenol oxidase originating from pear was evaluated to investigate whether polyphenol oxidase can be used as a valuable compound to improve the biological activity of gallic acid. Enzymatic oxidation processing of gallic acid using polyphenol oxidase was carried out for five different reaction times. The antioxidant effects of transformed gallic acid for different reaction times were evaluated via radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radicals. In addition, the anti-diabetic property of the transformed gallic acid was measured based on ${\alpha}$-glucosidase. Gallic acid reacted for 5 h showed significantly higher antioxidant and ${\alpha}$-glucosidase inhibitory activities compared to the tested positive control substances. Biotransformation of simple gallic acid induced by polyphenol oxidase might be responsible for enhancing the biological activity of gallic acid.

• Journal of Mushroom
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• v.16 no.3
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• pp.213-217
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• 2018

This study was carried out to identify medicinal mushrooms with protective effects against oxidative stress in PC12 neuronal cell line, followed by evaluation of their antioxidant property. Extracts of medicinal mushrooms, including Ganoderma lucidum extract (GLE), antler-shaped Ganoderma lingzhi extract (AGLE), Hericium erinaceus extract (HEE), and Sanghuangporus baumii extract (SBE), were screened for cytotoxicity using MTT assay. None of the extracts up to $10{\mu}g/ml$ concentration affected cell viability. These extracts were further checked for their protective effect against oxidative stress-induced reactive oxygen species (ROS) production. Exposure to $50{\mu}M$ $H_2O_2$ induced ROS generation in PC12 cells, which was inhibited only by treatment with AGLE. In addition, inhibition of $H_2O_2-induced$ ROS generation by AGLE was found to be in a dose-dependent manner (2.5, 5, and $10{\mu}g/ml$). Microscopic examination of DCF fluorescence for detection of ROS showed a similar pattern. Further, antioxidant activity of AGLE was determined by ABTS radical cation assay, and its $IC_{50}$ was found to be $46.90{\pm}0.31{\mu}g/ml$. Taken together, these results suggest that AGLE may help to alleviate oxidative stress in PC12 neuronal cells.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.293-298
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• 2013

We aimed to provide the basic data for the development of a beverage using the juices from bioresources from Jeju. Our results show that pH and $^{\circ}Bx$ of the bioresources ranged 2.0-6.5 and 3.3-16.8, respectively. Rubus coreanus Miquel juice had the highest total phenol content (47.3 mg gallic acid equivalent (GAE)/100 mL). Citrus sphaerocarpa juice showed higher rates of 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging (86.8%) than those of other juices. However, the oxygen radical absorbance capacity (ORAC) value ($2,409.5{\mu}M$ TE/mL) of Citrus sudachi Hort. ex Shirai juice was higher than those of other juices. A high correlation (R=0.7343) was observed between the pH and ORAC values for the 20 bioresources. Furthermore, a high correlation (R=0.8752) was found between the phenolic contents and DPPH radical scavenging for the 5 citrus fruits. These results suggest that the bioresources in Jeju could be used as natural antioxidants for the development of functional foods, including healthy beverages.

• Food Science and Preservation
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• v.24 no.7
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• pp.934-941
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• 2017

The objective of this study was to investigate the effect of corrugated packaging coated with aluminum (Al) on quality characteristics of red paprika during storage at $25^{\circ}C$. Characteristics such as weight loss, hardness, total phenolic content, antioxidant activities, polygalacturonic acid (PG) activity, and oxidative enzyme activities (polyphenol oxidase and peroxidase activities) of paprikas, packed in corrugated packaging with or without Al-coating were compared as a function of storage time. Al coating inside of corrugated box was found to inhibit PG activity, resulting in prevention of weight loss and maintenance of hardness of paprika during storage, compared to the control sample. This may be due to Al coating treatment that enhance moisture-proof property and hinder gas transmission of corrugated packaging. Furthermore, paprika in Al-coated-corrugated packaging was lower in oxidative enzyme activities than the control, which caused higher total phenolic content and antioxidant activities during storage. As a results, the Al coated-corrugated packaging can be used as a functional packaging material to extend the shelf-life and improve the storage quality of paprika by preventing their respiration and transpiration.

• Food Science and Preservation
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• v.24 no.2
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• pp.266-273
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• 2017

This study was carried out to investigate the quality characteristics and antioxidative activity of bread containing lotus leaf powder (in ratios of 0, 1, 2, and 3% of the total flour). The pH of dough and bread were decreased as the concentration of lotus leaf powder increased. The volume of dough during fermentation did not show significant difference between 1% lotus leaf powder containing dough and control. The weight of bread increased by addition of lotus leaf powder. The volume, specific volume and baking loss rate of the bread decreased as lotus leaf powder levels increased. Redness and yellowness of the inner crumb were decreased by the addition of lotus leaf powder, but lightness was increased. 2,2-diphenyl-1-picrylhydrazyl-radical scavenging activity and total polyphenol contents were increased significantly as the concentration of lotus leaf powder increased. The overall acceptability of bread containing 1% lotus leaf powder showed no significant difference compared with control. The result exhibited that adding the lotus leaf powder into the bread increased antioxidant activity, and the highest quality improvement was obtained by incorporating 1% (w/w) lotus leaf powder into the bread formula.

• Food Science and Preservation
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• v.24 no.5
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• pp.576-584
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• 2017

With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to $13^{\circ}Brix$. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at $4^{\circ}C$. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.39-48
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• 2018

The coffee silver skin is a part of coffee beans. We report that the coffee sliver skin extracts exhibited cosmetic properties of antioxidant, anti-winkle and whitening effects. The ethanol extracts of silver skin showed free radical scavenging activity up to 92.26% in $50{\mu}g/mL$, especially against DPPH radical and ABTS radical cation. The silver skin extracts showed inhibitory effects for tyrosinase activity and DOPA oxidation in a dose-dependent manner, suggesting the extracts retain for the whitening property in cosmetics. The coffee silver skin extracts effectively inhibited the elastase and collagenase. Cytotoxicity of the coffee silver skin extracts was measured by the colorimetric MTS assay. The viability of the human keratinocytes (HaCaT) treated with the coffee silver skin extracts was same as that of untreated cells, indicating the extracts are safe to human cells. Here, we suggest that the silver skin extracts of coffee bean could be a potential natural substance for anti-winkle, whitening, antioxidant properties for cosmetics.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.363-371
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• 2012

Sambucus williamsii var. coreana have been used as a traditional medical food. This research was conducted to investigate the antioxidants of S. williamsii var. coreana leave and stem extracts. Total phenolic content of S. williamsii var. coreana leaves and stem water extracts were 6.6 and 2.0 mg/mL. The EDA by DPPH free radical scavenging test of S. williamsii var. coreana leaves extracts were 99.5 and 89.7% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The stem extracts were 92.2 and 94.3% in water and ethanol extracts contained phenolic 200 ${\mu}g/mL$. The ABTS radical decolorization activity of water and ethanol extracts from leaves were 79.8 and 99.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 90.8 and 97.2% at phenolic 200 ${\mu}g/mL$. The antioxidant protection factor of water and ethanol extracts from leaves were 1.1 PF and 1.1 PF at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 1.4 PF and 1.0 PF at phenolic 200 ${\mu}g/mL$. The TBARs of water and ethanol extracts from leaves were 88.7 and 98.1% at phenolic 200 ${\mu}g/mL$ and water and ethanol extracts from stem were 93.6 and 90.6% at phenolic 200 ${\mu}g/mL$. The antioxidative activities of extracts from S. williamsii var. coreana leaves and stem were higher than BHT as positive control. These results suggests that S. williamsii var. coreana extracts have the greatest property as a natural antioxidative source.

• The Korean Journal of Food And Nutrition
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• v.34 no.6
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• pp.612-620
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• 2021

To increase the utilization of Centella asiatica (CA), enzymes such as cellulase and pectinase were added and the physicochemical properties of the treated CA were analyzed. In addition, apple-CA jam was prepared using the enzyme-treated CA, which had the best antioxidant properties, and the physicochemical and sensory qualities of the jam were measured. There was a high content of ascorbic acid, polyphenols, flavonoids, reducing sugar, amino acid, minerals and DPPH radical scavenging activity in the enzyme-treated group. The antioxidant component and activity in the jam prepared by adding enzyme-treated CA increased with an increase in the amount of enzyme-treated CA. In the soluble solids, the higher the amount of enzyme-treated CA, the higher the value, but there was no significant difference in pH. The sensory evaluation of the jam, in particular the taste, showed that the highest preference was observed when the enzyme-treated CA was added in the range of 5.0~6.7%, and the control group showed the lowest preference. There was no significant difference in flavor and spreadability among the treatment groups, however, the control group showed the highest color preference. In the overall acceptability, when 5.0% of enzyme-treated CA was added, the highest acceptability was shown.

• Polymer(Korea)
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• v.39 no.3
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• pp.493-498
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• 2015

For biomaterials for skin regeneration with minimized inflammatory response, high bioactivity and biocompatibility are highly required. Also, it should have a porous microstructure to improve cell adhesion and growth. In this study, we extracted a new collagen source from duck's feet which is by-product, and made the shape of sponges from duck's feet collagen (DC) to compare with DBP and SIS. To analyze physical and chemical property of the scaffold, SEM and FTIR were used. MTT assay was used to measure the attachment and proliferation of NIH/3T3 in the scaffolds. RTPCR was used to evaluate the expression of proinflammatory cytokine. Also, 1,1-diphenyl-2-picrylhydrazyl (DPPH) was used to measure the ability of antioxidant activity. Overall, this study shows that DC scaffold is biocompatible and has good physical property. Additionally, DC scaffold shows the potential as wound healing biomaterials.