• Journal of Life Science
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• v.25 no.4
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• pp.433-440
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• 2015

Several studies suggest that regular consumption of walnuts may have beneficial effects against oxidative stress-mediated disease such as cancer. The present study reports the total phenolic and flavonoid contents, together with the antioxidant and antibacterial activities of several solvent extracts (methanol, n-hexane, ethyl acetate, n-butanol, and water) obtained from walnut (Juglans regia L.) green husk. MIC (minimal inhibitory concentration) values of the walnut extracts for 8 human pathogenic bacteria strain were determined using agar dilution method. Antioxidant activity of extracts were assessed using DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) assays, EC₅₀ of DPPH and ABTS scavenging activities, and determination of total phenolic and flavonoid content and its correlation with DPPH and ABTS scavenging capacities. Among the six extracts, ethyl acetate extract (EtOAc Ex) showed the highest antimicrobial activity at 3.2 mg/ml of MICs against Staphylococcus aureus SG511. Total flavonoids and polyphenol contents of EtOAc Ex were 42.48 mg of quercetin equivalents (QE)/g and 223.25 mg of gallic acid equivalents (GAE)/g respectively. The highest antioxidative potential was shown by the sample extracted with EtOAc Ex (EC₅₀=13.43 μg/ml for DPPH and EC₅₀=41.83 μg/ml for ABTS radical scavenging activity assay). These results showed that J. regia green husk extracts can be used as an easily accessible source of natural antibacterial agents and natural antioxidants.

• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.386-391
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• 2009

To verify the possibility of manufacturing a germinated rough rice tea, germinated rough rice was roasted at 200, 220, and $250^{\circ}C$ for 10, 20, and 30 min. The treated rice powder was then put into tea bags and leached for 1, 3, and 5 min, after which their antioxidant, physicochemical, and sensory characteristics were compared. The total polyphenol content and 2,2'-Azino-bis-(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the germinated rough rice tea increased as the roasting temperature increased as well as in response to increased roasting and leaching times. Furthermore, the greater the roasting temperature, roasting time, and leaching time, the greater the increase in total soluble solid contents. Moreover, the turbidity and browning index of the germinated rice tea rose as the roasting temperature, roasting time, and leaching time increased. Additionally, the pH tended to decrease as the roasting temperature, roasting time, and leaching time increased. Evaluation of the sensory characteristics of the germinated rice tea revealed that the formation of a Maillard reaction product in the course of heating the rice added a unique flavor, which led to increase preference for the color, flavor, and taste, and therefore, the overall preference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.47-55
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• 2011

The solvent extracts of Aruncus dioicus var. kamtschaticus Hara, which were extracted by using several solvents with different polarities, were performed to investigate the antioxidant activities, whitening effect and antimicrobial activity. The content of total polyphenol of fractions from Aruncus dioicus var. kamtschaticus Hara extract showed the highest value ($335.88{\pm}2.26$ mg/g GAE) on ethyl acetate fraction. The ethyl acetate and n-butanol fractions were 0.06 mg/mL and 0.25 mg/mL as $IC_{50}$ values on DPPH radical scavenging, and $99.16{\pm}0.09%$ and $89.29{\pm}0.64%$ on ABTS radical scavenging activity, respectively. Also, reducing power and FRAP value were significantly higher on ethyl acetate fraction. The SOD like activity showed $80.76{\pm}0.61%$ on ethyl acetate and $72.34{\pm}0.79%$ on n-butanol. Tyrosinase inhibition activities (at 5 mg/mL) were $59.08{\pm}0.98%$ on ethyl acetate fraction. The chloroform fraction showed the strongest antimicrobial activities against B. cereus (14 mm), B. subtilis (12.5 mm), S. aureus (10.8 mm), E. coli (20.7 mm) at 0.1 mg/disc and the inhibition zone diameter of ethyl acetate fraction was 17.2 mm against E. coli at 0.5 mg/disc. The minimum inhibitory concentrations (MIC) of chloroform fraction against B. cereus and E. coli were 50 and $25{\mu}g$/mL, respectively. From these results, it is suggested that ethyl acetate and n-butanol fractions of Aruncus dioicus var. kamtschaticus Hara could be used as functional material for food additive ingredient and chloroform fraction could be suitable for the development of a food preservative.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.162-169
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• 2014

In the course of study for the development of functional food using red beans (azuki beans, Phaseolus radiatus L.), the ethanol extracts from raw-red bean (RRB) and boiled-red bean (BRB) were prepared, and the components and various biological activities of both were compared. It was observed that the extraction yield, and the total polyphenol content, of the BRB were 1.2 times higher than that of the RRB. However, the contents of total flavonoid, total sugar and reducing sugar in the BRB were 30, 27.9 and 30.8% respectively when compared with those of RRB. In relation to antioxidative activity, both RRB and BRB exhibited moderate DPPH anion, ABTS cation, and nitrite scavenging activities and reducing power, though in all cases RRB demonstrated stronger activities than BRB. The extracts of RRB and BRB did not reveal any antimicrobial activities. In a ${\alpha}$-amylase inhibitory activity assay, RRB was higher than BRB, while BRB showed higher ${\alpha}$-glucosidase inhibitory activity than RRB. A strong and particular activity was observed in an anti-thrombosis activity assay of RRB. The extract of RRB demonstrated strong inhibitions against prothrombin and blood coagulation factors, with moderate thrombin inhibition. However, the extract of BRB did not exhibit any significant anti-thrombosis activity. Our results indicate that RRB has different, but useful biological activities, and loss or elimination of the biologically active substances in RRB occurs during the production of BRB. Therefore, to develop more functional foods from red beans, a study of suitable boiling, heating and drying processes is essential, and the efficient re-use of boiled waste water from the boiling process is necessary. These results could be applied to the further development of functional red bean beverages and sweat red bean pastes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.214-220
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• 1993

Browning of ascidian, Halocynthia roretzi, meat occurres very rapidly when skinned off or cut during processing and it resulted the quality loss of fresh frozen, dehydrated or fermented products. In this study, the causes of color development and prevention of browning were experimented. The browning of ascidian meat may be occurred enzymatically by a tyrosinase contained in meat and viscera which acted specifically on L-tyrosine as a substrate rather than on catechol. Activity of the enzyme in viscera was three times higher than in meat. The optimum pH and temperature on the tyrosinase activity of crude enzyme obtained from ascidian was 6.0 and $30{\sim}35^{\circ}C$, respectively. The enzyme was inactivated heating at $80^{\circ}C$ for 3 minutes or $90{\sim}100^{\circ}C$ for 1 minute and it was inhibited by $0.1{\sim}0.5mM$ solutions at ascorbic acid, sodium hydrogen sulfite, cystein, citric acid, cyanide but only sodium hydrogen sulfite treatment was effective to retard such a high content of enzyme as in case of viscera. In practical use for processing of ascidian meat browning was retarded by dipping the viscera removed ascidian meat in 0.2M citric acid for 5 minutes or $0.2\%$ sodium hydrogen sulfite solution for 1 minute resulting in sulfur dioxide residue less than 100 ppm.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.463-472
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• 2019

This study investigated the quality characteristics and antioxidant activities of morning bread containing various amounts of aronia sourdough starter. Morning breads were prepared with different volumes (0% (AS0), 15% (AS1), 25% (AS2), and 35% (AS3)) of aronia sourdough starter based on wheat flour. In AS3 group (35% added group), the specific volume and baking loss rate were the highest but the bread height was the lowest. When the aronia sourdough starter was added up to 25%, the expansion power, specific volume, and bread height were significantly increased (P<0.05). According to the added amount of sourdough starters, the lightness and yellowness of the morning bread were decreased, however, redness was increased (P<0.05). In the rheology analysis, hardness, gumminess, and chewiness were significantly decreased with increasing amounts of aronia sourdough starters (P<0.05). However, cohesiveness was the highest in the AS2 group (25% added group). In consumer preference, the highest scores were shown in AS2 group (25% added group) in color, texture, and appearance. The total polyphenol and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability were both significantly increased along with aronia sourdough content (P<0.05). In conclusion, morning bread with 25% aronia sourdough starter showed the best quality characteristics and antioxidant activities.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.423-432
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• 2019

In order to select potential plant resources as functional materials and natural antioxidants, we evaluated antioxidant activity and serotonin derivatives of safflower germplasm collected from five countries. N-(p-Coumaroyl) serotonin (CS) and N-feruloylserotonin (FS) were analyzed by using Ultra Performance Liquid Chromatography (UPLC). Total polyphenol content (TPC) was determined by Folin-Ciocalteu method and antioxidant activities were estimated by 2,2-diphenyl-1-picryl-hydrazil (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), Ferric reducing antioxidant power (FRAP) and Reducing power (RP) assays. The TPC showed a range of 28.25 to $90.53{\mu}g$ gallic acid equivalent (GAE)/mg dried extract (DE). DPPH, ABTS, FRAP and RP assay were in the range of 18.76 to 93.98, 48.91 to 163.73, 3.80 to 132.29 and 26.32 to $80.08{\mu}g$ ascorbic acid equivalent (ASCE)/mg DE, respectively. Among the five countries, safflower seed collected from Iran had the highest levels of serotonin derivatives and antioxidant activities than other countries (p<0.05). CS showed high correlation with TPC, ABTS and DPPH (r=0.673,0.727,0.820), and FS showed high correlation with DPPH (r=0.740). Accessions IT321214 and IT321215 could be useful for development of new functional materials and could be used as a source of valuable natural antioxidant materials.

• Food Science and Preservation
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• v.19 no.6
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• pp.825-832
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• 2012

In this study, the quality characteristics and antioxidant activity of mulberry salad dressing prepared with yam juice during storage at $5^{\circ}C$ for four weeks were evaluated. The salad dressing was prepared with a salad base, mulberry, omija, and yam (4:4:6:1 or 4:4:6:3). Fresh yam juice was added to the salad dressing at 0, 7, and 18% levels. After four weeks storage, the pH increased whereas the acidity decreased. As the yam concentration increased, the pH increased to 3.84 and the acidity decreased to 0.14%. The Hunter color L (lightness), b (yellowness), and a (redness) values decreased over the storage period. After four weeks storage, the viscosity increased from 83.2 to 158.5 cp according to the amount of yam juice that was added. The antioxidant activity, such as the DPPH radical scavenging activity, and the total polyphenol content of the salad dressing improved as the yam concentration increased. Moreover, according to the storage time, the peroxide value did not increase. These results show that the mulberry salad dressing to which omija and fresh yam juice were added maintained its freshness with high antioxidative activity during storage.

• Food Science and Preservation
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• v.25 no.1
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• pp.79-89
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• 2018

In this study, the anti-oxidant, whitening, and anti-wrinkle effects of Castanea crenata inner shell extracts processed by enzyme treatment and pressurized extraction were investigated. The Castanea crenata inner shell was first hydrolyzed using celluclast, viscozyme, or hemicellulase. Then, it was subjected to pressure extraction for different durations (30, 60, and 120 min). The yields of the Castanea crenata inner shell extracts processed by different enzyme treatments followed by pressurized extraction for different times are in the range of 12.42-29.80%. The total polyphenol, flavonoid, and tannin contents of the C30m (celluclast enzyme and autoclave extracts at 30 min) extract were 15.48, 10.82, and 15.82 g/100 g, respectively. The total sugar content of the H120m(hemicellulase enzyme and autoclave extracts at 120 min) extract is 61.07 g/100 g. The 1,1-diphenyl-2-pycrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the C30m extract at $1,000{\mu}g/mL$ are 89.20, and 81.96%, respectively. The superoxide radical scavenging and ferric-reducing antioxidant power of the C30m extract at $1,000{\mu}g/mL$ are 67.63% and $1,324.79{\mu}M$, respectively. Further, the tyrosinase and elastase inhibition activity of the C30m extract at $1,000{\mu}g/mL$ are 61.32, and 61.06%, respectively. Our results indicate that the Castanea crenata inner shell extracts processed by enzyme treatment followed by pressurized extraction could have beneficial effects on facial skin and they should be considered for use in new functional cosmetics.

• Journal of Mushroom
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• v.19 no.3
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• pp.166-175
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• 2021

In this study, monokaryons of "Heukari" (Pleurotus ostreatus) and "Hosan" (Pleurotus pulmonarius) were separated to remove the cell wall, and a cross-species protoplast fusion was developed through chemical treatment with polyethylene glycol. The protoplast-fused PF160306 and PF160313 strains have a culture period of 10 and 2 days shorter than that of the "Heuktari" and "Hosan" cultivars, respectively. Furthermore, the growth of the strains was faster than that of the existing cultivars. The yield was 135.9 g per bottle, which was approximately 8% higher than that of the commercially available "Hosan" cultivar; however, it was not statistically significant. A growth survey was conducted after treatment at five temperatures (15, 18, 21, 23, and 25℃). The growth of the strains accelerated with the increase in temperature. However, at 21℃, the yellow color of pileus was the brightest. Band pattern, assessed using URP Primer 7, was similar to that of the "Hosan" cultivar. The DPPH radical scavenging capacity and polyphenol content were 62.5% and 43.5 mg/mL, respectively, for "Sunjung" and 65.7% and 49.9 mg/mL, respectively, for PF160313. Furthermore, the antihypertensive activities of the "Sunjung" cultivar and PF160313 were similarly high at 74% and 75%, respectively. In conclusion, cross-species hybridization via the protoplast fusion technique can be used for obtaining primary data for mushroom breeding to develop new varieties. In addition, the protoplast fusion technique might aid in expanding the market for yellow mushrooms.