• Journal of Microbiology and Biotechnology
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• v.30 no.11
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• pp.1697-1705
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• 2020

Meju, a type of fermented soybean paste, is used as a starter in the preparation of various Korean traditional soybean-based foods. In this study, we performed Illumina-MiSeq paired-end sequencing for microbial communities and mass spectrometry analysis for metabolite profiling to investigate the differences between 11 traditional meju products from different regions across Korea. Even though the bacterial and fungal communities showed remarkable variety, major genera including Bacillus, Enterococcus, Variovorax, Pediococcus, Weissella, and Aspergillus were detected in every sample of meju. The metabolite profile patterns of the 11 samples were clustered into two main groups: group I (M1-5) and group II (M6-11). The metabolite analysis indicated a relatively higher amino acid content in group I, while group II exhibited higher isoflavone, soyasaponin, and lysophospholipid contents. The bioactivity analysis proved that the ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was higher in group II and the FRAP (ferric reducing antioxidant power) activity was higher in group I. The correlation analysis revealed that the ABTS activity was isoflavonoid, lipid, and soyasaponin related, whereas the FRAP activity was amino acid and flavonoid related. These results suggest that the antioxidant activities of meju are critically influenced by the microbiome and metabolite dynamics.

• Journal of Korean Medicine Rehabilitation
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• v.30 no.4
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• pp.31-39
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• 2020

Objectives Danggwisoo-san and Jakyakgamcho-tang are frequently prescribed for traffic accident patients in Korea. The aim of this study was to examine index compound analysis, antioxidant activity and amount of starch measurement by extraction method. Methods Danggwisoo-san and Jakyakgamcho-tang were extracted with water and 70% ethanol. Antioxidant activity was measured by 2,2-Diphenyl-1-picrylhydrazyl, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power according to the standard protocol. The contents of the indicator components nodakenin, paeoniflorin, and glycyrrhizin were measured by high-performance liquid chromatography, respectively. All starches were hydrolyzed and then total D-glucose was measured and compared. Results Antioxidant activity was excellent in 70% ethanol in all assays. The index component was jagged because its solubility was different depending on the extraction solvent. Starch content was significantly lower in 70% alcohol extract than water extract. Conclusions The results of this study showed that physiological activities and components are different according to extraction conditions. Each herbal medicine has a suitable extraction solvent. Also, the difference in starch content is an object to be considered as it may affect digestion and absorption.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.129-137
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• 2020

This study aims to evaluate the efficacy of the Ultrasonication-Assisted (UA) extraction on the functionality of the herbaceous biennial plant maca (Lepidium meyenii). The specific objectives include comparison of the antioxidant activities among various maca extracts, determination of the macamide B content of the extracts, and in vitro evaluation of maca on cell viability and creatine kinase (CK) activity. The antioxidant activities of the water, ethanol, and UA extracts were compared by determining the total phenolic and flavonoid contents, the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities, and the ferric reducing antioxidant power (FRAP) of the extracts. The macamide B content of maca extracts were analyzed by HPLC. The effects of the extracts on muscle cell viability and creatine kinase activity were also determined using C2C12 myoblasts. UA extraction significantly increased the total phenolic content (2.90 GAE ㎍/mg, p < 0.05), without affecting the flavonoid content. DPPH radical scavenging activity did not exhibit any statistical difference among the extracts. The ethanol and UA extracts exhibited significantly higher FRAP than the water extract (p < 0.05). The macamide B content of ethanol and UA extracts were 0.087 and 0.083 ㎍/mg, respectively. The water and UA extracts exhibited higher C2C12 muscle cell viability than the ethanol extract, and both extracts resulted in a significantly lower CK level than the H₂O₂-treated control group. This research suggests that the maca extract can protect muscle cells and serve as an antifatigue agent under oxidative stress conditions.

• Journal of Mushroom
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• v.16 no.4
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• pp.311-317
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• 2018

The aim of this study was to identify chemical composition and antioxidant activity of phenolic extract of fruiting bodies of an artificially cultivated Hankyong Sanghwang mushroom, Phellinus linteus KACC 93057P (PLHS). The total phenolic content of 60% ethanolic extract of fruiting bodies of two-year-old PLHS grown on Oak wood logs was $19.05{\pm}0.32mg$ gallic acid equivalent (GAE)/g, which was 4-10 times high compared to the other species of mushrooms. 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbisthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and the ferric reducing antioxidant power (FRAP) value of PLHS were 2-10 and 5 times higher, respectively, than those of the other species of mushrooms. High performance liquid chromatography (HPLC) analysis of ethyl acetate fraction of 70% methanolic extract of the fruiting bodies of PLHS revealed the presence of styrylpyrone-class compounds, davallialactone, hispidin, hypholomine B, and caffeic acid, a compound of the phenylpropanoid pathway.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.378-388
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• 2022

This study was conducted to determine the proximate compositions, nutritional components, and antioxidant effects of white and brown enoki mushrooms (Flammulina velutipes). The crude protein and carbohydrate contents were higher in the brown than white mushrooms, whereas the moisture, crude ash, crude lipid, and dietary fiber levels were lower. The mineral contents of the white mushroom was higher than levels obtained in the brown mushroom for the detected components (Ca, Cu, K, Mn, Na, and P). The amount of vitamin B₃ in the brown mushroom was 1.51 mg/100 g, which was 4.5 times higher than that in the white mushroom. The major fatty acids detected were palmitic acid, linoleic acid, and α-linolenic acid. The total polyphenol and flavonoid contents were highest in 70% ethanol extracts of the white and brown mushrooms, respectively. For the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, a 70% methanol extract of the white enoki mushrooms showed an activity of 76.4% (p<0.05). For the ferric-reducing antioxidant power (FRAP) activity, a 70% methanol extract of the brown enoki mushrooms showed the highest value. Further, the total flavonoid contents were significantly correlated with the DPPH and FRAP activities.

• Food Science and Preservation
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• v.30 no.3
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• pp.369-382
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• 2023

We examined the changes in the physicochemical quality characteristics and antioxidant activity of fresh-cut Fuji apples (Malus pumila) during processing and storage after treatment with browning inhibitors. The primary aim was to elucidate processing suitability and storability. We observed that in the processing stage of slicing fresh Fuji apples, there were no significant differences in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability and ferric-reducing antioxidant power (FRAP). However, after NaClO treatment, total flavonoid and total polyphenol contents decreased. When freshcut Fuji apples were treated with browning inhibitors and stored at 4℃, the L value and hardness decreased; however, the weight loss rate increased based on the storage period of all fruit groups treated with Citrus unshiu Markovich (CuM), calcium ascorbate (CA), and ascorbic acid (AA). The pH increased after 2 days of storage in 1% CuM and after 6 days of storage in 1% CA; however, no changes in pH were observed during the storage period in 1% AA. The DPPH radical scavenging activity was generally good under storage conditions of 1% AA at 4℃ and 1% CA at 20℃. Furthermore, FRAP remained relatively constant under storage conditions of 1% CA. The quality characteristics and antioxidant activity of fresh-cut fruits during processing and storage can be used as basic data for industries. Furthermore, we can gain confidence in quality improvements by improving the production and distribution environment of fresh-cut agricultural products.

• Food Science and Preservation
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• v.16 no.3
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• pp.333-341
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• 2009

The antioxidant properties of green tea leaves and powder extracts were determined using several tests including estimation of reducing power, DPPH(1,1-diphenyl-2- picrylhydrazyl) radical-scavenging activity, and FRAP(Ferric reducing/antioxidant power) assay. All tests indicated that extracts of green tea powder had higher antioxidant activities than extracts of green tea leaves, and the activities were concentration-dependent. However, each test yielded somewhat different results with respect to storage conditions. The reducing power of green tea leaves was highest at $1,000{\mu}g/mL$, storage at $4^{\circ}C$, and an Aw(water activity) value of 0.23. However, the reducing power of green tea powder, assayed at $1,000{\mu}g/mL$, was high under all storage conditions(with variations in temperature and Aw), and was about 1.5.2-fold greater than that of green tea leaves. Radical-scavenging activity, as assessed by the DPPH assay, increased in a dose-dependent manner over the range $15{\sim}125{\mu}g/mL$. At higher concentrations, activities were $80{\sim}90%$ of maximal were attained. The FRAP activity of green tea extract also increased with rising concentration. Particularly in the case of green tea leaves, antioxidant activity was most greatest with storage at $-20^{\circ}C$ and Aw values of 0.69 and 0.23 when assayed at a concentration of $1,000{\mu}g/mL$. These results indicate that the most important factor during storage of green tea is not the Aw value but rather temperature, and that use of refrigeration($4^{\circ}C$) is preferable to increase or maintain the antioxidant activities of biological components in green tea.

• Food Science and Preservation
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• v.22 no.3
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• pp.421-427
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• 2015

Oriental melon (Cucumis melo L. var. makuwa) has been widely consumed as various processed foods, such as dried products, jelly, wine, juice, and vinegar, in Asian countries. In fruit processing, blanching and pressure treatments affect its quality, such as antioxidant activities, sensory characteristics, and etc. This study was conducted to evaluate the effects of blanching and pressure pre-treatments on oriental melon wine-making (BP, blanching and pressure filtration; BNP, blanching and non-pressure filtration; NBP, non-blanching and pressure filtration; and NBNP, non-blanching and non-pressure filtration). Physicochemical properties and antioxidant capacities by ${\alpha}$, ${\alpha}$-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing antioxidant power (FRAP) assay, and total phenolic and total flavonoid contents were measured for comparison of the different pre-treatment methods. After the aging process, the alcohol contents and pH values showed no statistical differences, whereas the amount of soluble solids, reducing sugar, and titratable acidity were slightly different among the pre-treatments (p<0.05). The samples with blanching pre-treatment showed higher antioxidant capacities than those of other pre-treatments. In the sensory evaluation, the BNP was the best in overall acceptability. Thus, this study showed that the blanching treatment enhanced the antioxidant capacities and sensory qualities of the oriental melon wine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.202-208
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• 2016

The physicochemical properties and antioxidant activities of fermented mulberry by lactic acid bacteria were investigated. The viable cell counts of lactic acid bacteria slowly increased up to 8.31 log CFU/mL. The pH and titratable acidity were 3.90 and 0.15%, respectively, after 24 h of fermentation. Color in terms of L and a values decreased, whereas b and ${\Delta}E$ values increased. The total anthocyanin contents of fermented mulberry (171.40 mg/100 g) was higher than that of mulberry (144.70 mg/100 g). The cyanidin-3-glucoside and cyanidin-3-rutinoside contents of fermented mulberry were 61.39 mg/100 g and 85.45 mg/100 g, respectively. Total phenolic and flavonoid contents of fermented mulberry (10.75 g/100 g and 5.02 g/100 g, respectively) was higher than those of mulberry (4.53 g/100 g and 1.77 g/100 g, respectively). The oxygen radical absorbance capacity of fermented mulberry was $292.94{\mu}M/g$. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide radical scavenging activity of fermented mulberry at $250{\sim}2,500{\mu}g/mL$ were 17.40~58.21% and 32.63~87.34%, respectively. The ferric reducing antioxidant power and reducing power of fermented mulberry at $250{\sim}2,500{\mu}g/mL$ were $37.03{\sim}762.13{\mu}M$ and 0.12~0.74, respectively. The results suggest that mulberry fermented by lactic acid bacteria has potential as functional materials in food industry.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.60-66
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• 2020

This study examined the antioxidant activity and neuroprotective effects of ethanol extracts obtained from Diospyros kaki core (DCE). The total polyphenol and flavonoid contents in DCE was 786.47±15.27 and 31.14±0.82 mg/g, respectively. In addition, DCE exhibited a dose-dependent induction of radical scavenging activity, determined by 1,1-diphenyl-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonicacid) (ABTS), ferric reducing antioxidant power (FRAP), and reducing power assays. The viability of HT22 hippocampal cells was examined to investigate the neuroprotective effect of DCE. DCE treatment did not induce cytotoxicity at concentrations below 1,000 ㎍/mL. Additionally, DCE treatment in the background of H₂O₂ induce oxidative stress revealed a significant increase in the survival rat, indicated by increased SOD activity and decreased levels of MDA, a lipid peroxidation product. Therefore, the results suggest that DCE can be used as a source of natural antioxidants source and a therapeutic agent for the treatment of brain disorders induced by oxidative stress and neuronal damage.