• Horticultural Science & Technology
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• v.30 no.2
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• pp.208-213
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• 2012

This study was performed to compare antioxidant activities of 80% EtOH extracts from young and mature fruit of three pear cultivars ('Wonhwang', 'Whangkeumbae', and 'Chuwhangbae') classified by three parts (peel, core, and flesh) of mature fruit. The total phenolics compound and flavonoid contents of 80% EtOH extracts from young fruit were 1.5-2.5 times higher than the mature fruit with great cultivar difference. In particular, the contents of those compounds were highest in 'Chuwhangbae' pear. The total phenolics compound and flavonoid contents of 80% EtOH extracts from mature fruit were the most in the peel, core, and flesh respectively. DPPH radical scavenging and $ABTS^+$ radical scavenging of 80% EtOH extracts from the young fruit were higher than the mature fruit of 'Chuwhangbae' pear. DPPH radical scavenging and ABTS+ radical scavenging of 80% EtOH extracts from mature fruit were the highest in the peel, core, and flesh respectively.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.857-864
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• 2013

This study was investigated the effects of heat treatment on polyphenolic compounds and antioxidant activities of yacon. Raw yacon was heated at $100^{\circ}C$ and $121^{\circ}C$ for 15, 30, or 60 min by using an autoclave. The browning intensity, levels of free and bound phenolic and flavonoid compounds, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical-scavenging activity of yacon extracts following heat treatment were measured. The browning index, free polyphenolic content, and antioxidant activities in the extracts were significantly increased (p<0.05) with both increased heating temperature and time, while bound polyphenolic levels were decreased. The levels of free phenolic and flavonoid compounds in the yacon extract heated to $121^{\circ}C$ for 60 min were increased by 1.2 and 1.1 folds compared to raw yacon respectively. Moreover, DPPH and ABTS radical-scavenging activities of the yacon heated to $121^{\circ}C$ for 60 min were 1.7 fold and 2.0 fold higher, respectively, than those of raw yacon. A significant (p<0.01) correlation was observed among browning intensity, free and bound phenolic and flavonoid levels, and DPPH and ABTS radical-scavenging activities in heated yacon extract. Thus, heat treatment can be used as a method to enhance the antioxidant compound content in and the antioxidant activity of yacon.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.283-289
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• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.548-556
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• 2013

The objective of this study was to determine the effect of antioxidant enzyme activity and radical scavenging activities of cucumber grown greenhouse. The analytic method of antioxidant activities were measured by estimating DPPH free radical scavenging, nitrite scavenging ability activity and ABTS radical scavenging ability. The DPPH free radical scavenging activity of Jangjukcheongjang was the highest in most of the growth stage. The Nitrite scavenging ability at pH 1.2 was more than 40% in all cultivars and growth stages. The ABTS radical scavenging ability of Jangjukcheongjang and Nulpureuncheongjang showed relatively little higher than Janghyeongnakhap and Sinjoeunbaekdadagi. The SOD activity showed higher activity than 95% in all cultivars and growth stages. The activity of CAT was highest in the Nulpureuncheongjang of 2 (12~16cm) growth stage, and the APX activity of Nulpureuncheongjang and Janghyeongnakhap showed a relatively high activity. The POX activity showed distinctly different trends depending on the growth stage, and that is, the activity at harvest stage was significantly reduced. These results suggest that the cucumber had the potent biological activities, and that in the future, the availability of cucumber will be increase in the field of high-value cosmetic and food products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1948-1953
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• 2014

This study examined changes in antioxidant activity as well as contents of rosmarinic acid, homoplantaginin, and luteolin, which is the main substance of Salvia plebeia R. Br. (SPR) known to have anti-inflammatory efficacy, according to drying, blanching, and fermentation conditions. Rosmarinic acid content was 16.42 mg/g upon hot-air drying and 10.19 mg/g upon hot-air drying after blanching, and there was no significant difference in the case of leaf and root freezing or cold-air drying. Rosmarinic acid content was 8.69 and 8.15 mg/g in the case of air-drying in the shade and freeze-drying, respectively, and decreased to 0.05 mg/g or undetected after fermentation. SPR processed by freeze-drying, cold-air drying in the shade, and hot-air drying showed ABTS radical scavenging ability over 98.5% at a concentration over $500{\mu}g/mL$ as well as excellent radical scavenging ability of 87.3% in the case of hot-air drying after blanching. Root showed lower ABTS radical scavenging ability than leaves. SOD-like activity was measured to be 6.1~27.8% at a concentration of $1,000{\mu}g/mL$, which was significantly difference from ABTS radical scavenging ability. As rosmarinic acid and homoplantagine, an anti-inflammatory material contained in SPR, are almost undetectable after oxidation fermentation during processing, hot-air drying after blanching or drying seems to be suitable to develop SPR as a functional substance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.5
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• pp.555-560
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• 2009

Pine mushroom (Tricholoma matsutake Sing.) is an expensive and highly prized delicacy in Korean and Japanese cuisines with its unique flavor and functional properties. The pine mushroom juice (PMJ) was investigated for its antioxidant and anti-tumor activities with ABTS radical scavenging method and MTT assay. The phenolic contents in pine mushroom juice ranged from 1.19 to 54.99 GAEs mg/100 mL at the concentrations of $1{\sim}50\;mg/mL$. The ABTS radical scavenging activities of pine mushroom juice were 7.0%, 81.7% and 91.8% at the concentrations of 1, 10 and 50 mg/mL, respectively. The $IC_{50}$ values of pine mushroom juice were 605.9, 788.4, 583.6 and $232.5{\mu}g/mL$ on the cytotoxicities against AGS, HeLa, HepG2 and HT-29, respectively, and PMJ showed the strongest growth inhibitory activity against HT-29 cell. These results suggested therapeutic potential for pine mushroom juice as an anti-oxidant and anti-tumor agent.

• Korean Journal of Plant Resources
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• v.23 no.2
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• pp.123-130
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• 2010

Present studies were conducted to investigate the effects of autoclaving on antioxidant activities of Achillea alpina and Solodago virgurea. At early April, young leaves of 2 species were collected, subjected to autoclaving ($121^{\circ}C$, 1.2 atmospheric pressure, 15 minutes), freezed-dried, grinded, and extracted with 80% ethanol. The same process was repeated with unautoclaved control. Total polyphenol and flavonoid contents, scavenging activities on DPPH and ABTS radicals and ferrous ion chelating effects were analyzed. Extraction yield of autoclaved S. virgurea was 39.55% and A. alpina 28.15%. In both species, autoclaving significantly reduced scavenging activities on DPPH and ABTS radicals. On the contrary, ferrous ion chelating effects increased after autoclaving, especially in young leaves of A. alpina. Autoclaving resulted in decrease of polyphenol and flavonoid contents, especially in the A. alpina. The present experiments demonstrated that autoclaving had negative effects on antioxidant activities of A. alpina and S. virgurea, except in ferrous ion chelating effects. Young leaves of former species were unstable to heat treatment, resulting in big lose of antioxidant activity.

• Food Engineering Progress
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• v.21 no.4
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• pp.326-331
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• 2017

A cultivar (Malus domestica cv. Fuji) of apple was selected to make apple peel (AP) powder by three different powdering methods. Frozen AP was thawed and subsequently was dried or ground without drying. After AP was dried by hot-air drying at $60^{\circ}C$ or freeze-drying, the dried AP was ground using a conventional blender. Separately, the thawed AP was powered by using a cryogenic micro grinding technology (CMGT). The ground AP and three types of AP powder were extracted using deionized water, 20, 40, 60, 80, or 100% methanol, followed by vacuum evaporation. The total phenolics contents (TPC), total flavonoids contents (TFC), DPPH, and ABTS radical scavenging capacities of each extract were compared to determine an efficient powdering method. Lyophilized AP powder extract using 60% methanol showed the highest TPC and DPPH radical scavenging capacity. In contrast, 60% methanol extract of the powder by CMGT, resulting in the smallest particle, exhibited the highest TFC and ABTS radical scavenging capacity. This study suggests that the extraction yield of bioactive compounds from AP may be varied according to different powdering methods and that a new powdering process such as CMGT may be applicable to develop functional foods efficiently.

• KSBB Journal
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• v.23 no.4
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• pp.297-302
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• 2008

In this work, the amounts of Flavone C-glycosides homoorientin, orientin extracted from Black bamboo by various ultrasonic waves frequency (35, 72, 170 KHz, 300 Watt $\pm$1) time (15, 30, 60 min) and temperature ($25^{\circ}C$) were compared using 50% aqueous ethanol solution. And describesanalysis of the antioxidant potential of Black bamboo using an high-performance liquid chromatography (HPLC) on-line $ABTS^+$antioxidant screening method. In conjunction with the analysis of their 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^+$) radical scavenging ability. The optimum operating conditions were experimentally determined to analyze the Flavone C-glycosides homoorientin, orientin in the pretreatment ultrasonic extracts. From the results, the effect on extraction yield of variations in frequency, solvent composition and extraction time was investigated. The highest yield of Black bamboo was obtained by ultrasonic waves with a frequency of 72 KHz and an extraction time of 60 min, The extraction frequency 35 KHz ($25^{\circ}C$), time 30 min was selected as an optimal antioxidant activity condition.

• Korean Journal of Pharmacognosy
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• v.44 no.4
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• pp.362-367
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• 2013

Ojeok-san has been commonly used to treat low back pain disease. We performed the experiments on simultaneous analysis of 11 compounds and antioxidant effects of Ojeok-san. A HPLC method was established for simultaneous analysis of 11 compounds. The detection wavelengths were set at 230, 254, 280, 320, and 330 nm. The detected 11 compounds from Ojeok-san water extract showed good linearity($r^2{\geq}0.9997$). Limit of detection(LOD) and limit of quantification(LOQ) were 0.04-0.87 ${\mu}g/mL$ and 0.13-2.63 ${\mu}g/mL$, respectively. The antioxidant effects of Ojeok-san water extract were investigated by DPPH and ABTS assays. Ojeok-san water extract significantly increased the DPPH and ABTS radical scavenging effects in a dose-dependent manner. The $RC_{50}$ value of Ojeok-san on DPPH radical was 284.71 ${\mu}g/mL$ and that of ABTS radical was 96.16 ${\mu}g/mL$.