• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.356-363
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• 2013

Clinical and preclinical trials of involving drugs with anti-obesity effects have focused on screening for herbal medicines suspected to have anti-obesity activities. In this study, an extract of Aster scaver Thunb., which was prepared in 80% methanol (ASE), was assessed for its total phenol content, total flavonoid content, antioxidant activity ability to scavenge the ${\alpha}-{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl, 2,2'-azino-bis-[3-ethylbenzthiazoline]-6-sulfonic acid radical, and anti-adipogenic effects. The anti-adipogenic effect of ASE on the differentiation of 3T3-L1 pre-adipocytes to adipocytes was investigated by assaying the suppression of adipocyte differentiation and lipid accumulation by using western blot analysis and the Oil Red-O assay, respectively. The staining results showed that ASE significantly inhibited 3T3-L1. Western blot analysis results showed that ASE decreased the levels of peroxisome proliferator-activated receptor-${\gamma}$, CCAAT/enhancer-binding protein ${\alpha}$, and sterol regulatory element-binding protein 1c. These results demonstrate that ASE directly inhibits the differentiation of preadipocytes, and might be an important adjunct in the therapeutic efforts to reduce adipogenesis.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.671-676
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• 2014

This study was designed to evaluate the changes in the physicochemical properties and antioxidant activity of Dutch coffee (cold brew) under different conditions of extraction and storage. Dutch coffee was extracted from ground coffee soaked in water at 4 or $20^{\circ}C$ and stored for 8 weeks at 4 or $20^{\circ}C$. The storage temperature affected the decline in pH and increase in acidity compared to the extraction temperature. The total phenol content partly decreased during the storage period. As the extraction temperature increased, the ABTS [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activities also increased; in fact, DPPH radical-scavenging activity showed a general increase. As the storage time prolonged, the caffeine content decreased, but the contents of caffeic acid and chlorogenic acid increased. The results for all kinds of samples indicated that the general bacterial count was <1 CFU/mL, which indicated that the coffee can be stored for and consumed within 8 weeks.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.474-479
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• 2017

Five types of coffee bean, which are usually imported and consumed in Korea, were roasted at $250^{\circ}C$ for 15 min and extracted by using a filter coffee machine. The physicochemical properties, functional components, and radical scavenging activity of coffee bean extracts were investigated. The pH of extract was the highest among the extracts and the soluble solid contents of extracts were $0.9-1.0^{\circ}Bx$. The acidity of the extracts was in the range from 0.46-0.55%, which was not significantly different from the control. Indonesian coffee bean extract showed the highest brown color intensity and contained the highest amounts of caffeine and chlorogenic acid. The highest total polyphenol content was found in Kenyan coffee bean extract. Coffee bean extracts from Indonesia and Kenya showed significantly higher radical scavenging activities than the other extracts. This study showed that coffee bean extracts from Indonesia and Kenya contained a large number of bioactive compounds and high antioxidant activity.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.135-142
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• 2018

We investigated the influence of germination and high hydrostatic pressure (HHP) treatment conditions on the conversion of functional compounds and antioxidant activity in adzuki bean. The adzuki bean germinated at $25^{\circ}C$ for three- or six-days, and was later subjected to HHP at 0.1, 50, 100, or 150 MPa for 24 h. The highest polyphenol content (5.36 mg gallic acid equivalents (GAE)/g) and flavonoid content (0.91 mg catechin equivalents (CE)/g) were observed after germination for six days and HHP treatment at 100 MPa for 24 h, respectively. The total phenolic acid contents increased with increasing applied pressure from 88.86 to $208.26{\mu}g/g$ (100MPa, 24h). Phenolic acids are divided into two categories; those that exhibit increased content upon HHP treatment, and those that exhibit decreased content. The increasing phenolic acids were gallic acid, chlorogenic acid, (+)-catechin, ${\rho}-coumaric$ acid, ferulic acid, heperidin, salicylic acid, protocatechuic acid, cinnamic acid, naringenin. The total anthocyanin content decreased with increasing applied pressure from 22.42 mg/100 g to 6.28 mg/100 g (150 MPa, 24 h). The highest ABTS radical scavenging activity (8.02 mg eq AA/g) and DPPH radical scavenging activity (1.22 eq Trolox/g) were observed after germination for six days and HHP treatment at 100MPa for 24h, respectively. These results suggested that the combination of HHP and germination can lead to improved functionality in adzuki bean.

• KSBB Journal
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• v.32 no.1
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• pp.63-70
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• 2017

Bamboo leaf has many nutritional and bioactive compounds such as polyphenols, and it can be used for various foods application. Fermentation is one of appropriate processes that can affect the nutrition, taste and flavor, and antioxidant activities of foods. In this study, a representative domestic bamboo tree (Sasa coreana Nakai) leaves were fermented by Bacillus subtilis KCCM 11315 and the changes of carbohydrates, minerals, amino acids, and phenolic compounds and antioxidant activities were investigated before and after fermentation. During the fermentation period, firstly, the leaf was softened and turned to brown. The constituent carbohydrates were slightly increased from $432.09{\pm}5.38mg/g$ to $458.42{\pm}7.39mg/g$, and free sugars decreased by 95% from $28.12{\pm}2.03mg/g$ to $1.4{\pm}0.14mg/g$. Mineral was $20987.5{\pm}345.1{\mu}g/mL$, which was slightly increased after the fermentation compared to $20804.1{\pm}364.6{\mu}g/mL$ before that. The total amino acids were increased to $73881.94{\pm}137.59mg/100g$ compared to $58464.51{\pm}109.12mg/100g$ before fermentation, and free amino acids decreased by more than 85% from $32782.67{\pm}92.49mg/100g$ to $4827.83{\pm}19.76mg/100g$. Total polyphenols content (TPC) increased from $25.51{\pm}1.04GAE^*mg/g$ to $35.34{\pm}0.91GAE^*mg/g$, and the total flavonoid content (TFC) increased to $80.57{\pm}0.22QE^*mg/g$ compared to $69.64{\pm}0.26QE^*mg/g$. The total catechin content (TCC) of TFC was decreased from $69.64{\pm}0.94mg/L$ to $58.23{\pm}0.76mg/L$. The DPPH radical $IC_{50}$ of bamboo leaves decreased to $2624.85{\pm}37.03{\mu}g/mL$ and the ABTS radical $IC_{50}$ of $187.26{\pm}4.78{\mu}g/mL$ was increased after the fermentation. These results could be used as essential nutritional data before developing processed food products using the bamboo leaf.

• Food Science and Preservation
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• v.22 no.3
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• pp.408-420
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• 2015

This study investigated the effect of heat treatment conditions on the quality and antioxidant activities of Korean traditional actinidia (Actinidia arguta) cultivars puree. Heat treatment on actinidia puree was conducted at $70{\sim}90^{\circ}C$ for 1 min to 5 mins, while a control sample of the actinidia puree was prepared without heat treatment. In all the samples, except for the sample treated at $90^{\circ}C$ for 5 mins, pH and Brix degree was not dramatically changed. Pulp content decreased with increasing temperature and time. L and the a value of color increased with increasing temperature and time. However, the b value showed a reverse tendency with L and the a value. Viscosity and gumminess increased as heat temperature and time increased, though cohesiveness was not significantly changed depending on temperature and time. Coliform and yeast were not detected on all samples and the number of aerobic bacteria and mold decreased as temperature and time increased. Vitamin C and total phenolic content of the puree was not changed for 1, 3, and 5 mins at $70^{\circ}C$ and for 1 and 3 mins at $80^{\circ}C$, but significantly decreased with increasing time at $90^{\circ}C$. Furthermore, the antioxidant activities of the puree, such as DPPH radical scavenging activity, ABTS radical scavenging activity, and FRAP (ferric reducing antioxidant power) showed a similar tendency with total phenolic content.

• Food Science and Preservation
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• v.24 no.7
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• pp.965-974
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• 2017

This study was carried out to investigate the effect of particle size of naked oat flour (NOF) on physicochemical property and antioxidant activity. The NOF was passed through $250{\mu}m$ and $160{\mu}m$ size sieves to obtain three fractions (fraction A: $250{\mu}m$ or more, fraction B: $160-250{\mu}m$, and fraction C: $160{\mu}m$ or less). Moisture, crude protein, crude fat, and crude ash contents of NOF were 8.4, 15.7, 10.0, and 1.8%, respectively, and these contents were increased as the particle size of NOF decreased. The mineral and free amino acid contents of NOF also had a similar tendency. The contents of total starch, amylose, starch damage, total dietary fiber, ${\beta}$-glucan, total phenolics, and flavonoids in NOF were 56.4%, 21.4%, 11.7%, 11.0%, 4.7%, $237.8{\mu}g/g$ and $90.9{\mu}g/g$, respectively. As the particle size of NOF decreased, total starch, amylose, and starch damage contents increased, whereas total dietary fiber, ${\beta}$-glucan, total phenolic and flavonoid contents decreased. Also, three antioxidant activities of NOF were closely correlated with their total phenolics and flavonoids contents, showing high correlation coefficient values ($R^2=0.87$ and 0.81, respectively).

• The Korean Journal of Food And Nutrition
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• v.29 no.2
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• pp.178-185
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• 2016

This study was designed to develop and to qualify a coffee alternative beverage using a mixture of coffee beans and roasted black beans (Rhynchosia nulubilis). Therefore, the total isoflavone content (TIC), total phenol content (TPC), antioxidant activity, anti-inflammatory activity, NFATc1 (Nuclear factor of activated T-cells c1) expression in RANKL (receptor activator of nuclear factor kappa-B ligand)-stimulated RAW264.7 cells and sensory evaluation were measured for 5 different Cb (coffee bean)-RoS (roasted seomoktae) mixture extracts (Cb100RoS0, Cb75RoS25, Cb50RoS50, Cb25RoS75, and Cb0RoS100). Cb0RoS100 had the highest TIC ($516.83{\pm}36.61mg/100g$) and TPC ($18.11{\pm}1.77mg$ TAE/100 g) along with the highest antioxidant activity as measured by DPPH radical scavenging activity ($73.55{\pm}8.11%$) and ABTS radical scavenging activity ($63.27{\pm}7.27%$). Also, Cb0RoS100 showed the highest anti-inflammatory activity as measured by NO production ($13.57{\pm}2.21{\mu}M$) and PGE2 production ($3.25{\pm}0.21ng/mL$). The more the RoS ratio was increased in the mixtures of Cb-RoS, the more the NFATc1 protein expression was decreased in RANKL-stimulated RAW264.7 cells. In case of sensory evaluation, Cb50RoS50 had the highest scores for flavor, delicate flavor and overall quality, which were similar to those in Cb alone (Cb100RoS0). We suggest that the use of RoS replacement instead of Cb in/as a coffee alternative beverage may help to reduce the risk of caffeine-related bone loss and/or bone disease by effectively blocking NFATc1 expression in RANKL-stimulated RAW264.7 cells compared with Cb alone.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.259-265
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• 2020

Antioxidative activities of 50% ethanolic extracts from Du-zhong (Eucommia ulmoides Oliver) leaf and bark were investigated. Yields of the leaf and bark extract were 8.1±0.31 and 17.4±0.89%, respectively. Polyphenol contents of the leaf and bark extract were 64.1±3.35 and 42.4±2.38 ㎍ gallic acid equivalents/mg, respectively. Flavonoid contents of the leaf and bark extract were 24.0±3.15 and 36.7±3.18 ㎍ quercetin equivalents/mg, respectively. As concentration of the leaf and bark extract increased, their antioxidative activities proportionally increased. EC₅₀ values of the leaf and bark extract for cation radical scavenging were 560.6±17.65 and 1,357.4±8.45 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for free radical scavenging were 574.2±14.70 and 2,103.1±108.59 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for ferric reducing antioxidant power were 319.9±13.42 and 705.9±26.08 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for nitrite scavenging were 2,329.2±35.11 and 5,467.6±243.92 ㎍/mL, respectively. In the presence of 74.8 ㎍/mL of the leaf extract and 177.2 ㎍/mL of the bark extract, linoleic acid peroxidation was inhibited by 70.0 and 79.1%, respectively. The Du-zhong leaf extract possessed higher antioxidative activities than its bark extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1637-1644
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• 2015

To develop health-functional food ingredients for improvement of diabetes, we examined biological activities, including total contents of polyphenols and flavonoids, antioxidant activity, and inhibition of ${\alpha}$-glucosidase and pancreatic lipase activities of ethanol extracts from unripe fruit of Momordica charantia L. cultivated in Hamyang, Korea. Ethanol extracts were tested using different ethanol concentrations (0%, 30%, 50%, and 70%) and temperatures ($50^{\circ}C$ and $70^{\circ}C$). Experimental results showed that total polyphenol and flavonoid contents were achieved concentrations of 7.77 mg/g (tannic acid), 7.66 mg/g (gallic acid), and 10.66 mg/g (rutin). The hydroxyl radical scavenging, ABTS cation radical scavenging, and FRAP activities were 82.19%, 42.82%, and 0.19 under the same conditions, respectively. The highest inhibitory activities of ${\alpha}$-glucosidase and pancreatic lipase were achieved in the 70% ethanol extract at $70^{\circ}C$. These results will be useful for development of health functional foods for anti-diabetes using 70% ethanol extract from unripe fruit of bitter melon.