• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.539-546
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• 2016

The aim of this study was to analyze antioxidant activity, total phenolics, and vitamin C content in unripe and ripe jujube cultivar and to investigate correlation between antioxidant and chemical constituents including total phenolics and vitamin C. The antioxidant activity was measured by the DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power. Although, the weight, diameter and soluble solids of Zyziphus jujuba fruit were increased with the progress of ripening, antioxidant activity and total phenolics were decrease during ripening. The highest free-radical scavenging activity (at 2.5 ㎎/㎖) and reducing power (at 1 ㎎/㎖) in fruit were 81.75% (Bokjo, unripe) and 0.80 (Mudeung, unripe), respectively. The highest total phenolic content in unripe fruit of Mudeung was 62.50 ㎍/g. A linear correlation (r=0.911) was shown between DPPH radical scavenging activity and total phenolic content.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.513-518
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• 2009

This study was carried out to investigate the changes of yield, total phenolics, saponin content and composition, antimicrobial, and antioxidant activities of various fractions of fine ginseng root (Panax ginseng C.A. Mayer) by maceration method in the order of increasing polarity (hexane, chloroform, ethyl acetate, butanol, and water). Butanol fraction showed the highest total saponin content compare to other fractions. Hexane fraction could harvest significantly high ginsenoside Rg2, Rg1, and Rf (p<0.05). And the contents of ginsenoside Rh1, Rg3, and Rg1 showed relatively higher in the fraction of ethyl acetate than other fractions. The system of hexane-chloroform-ethyl aceate-butanol showed relatively high content of ginsenoside Re, Rd, Rc, Rb3, and Rb1. However, the last fraction of water still remained lots of Rb2 content. The fraction of water was the highest phenolics. The 1,1-diphenyl-2-picryhydrazil, superoxide, and hydroxyl radical scavenging activity of water fraction was higher than the other fractions. In antimicrobial activity, the fraction of hexane showed relatively high antimicrobial activity against Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus, and Escherichia coli. And the fractions of the chloroform and ethyl acetate showed higher antimicrobial activities than the other samples in against P. aeruginosa and S. typhimurium.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.207-213
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• 2019

This study was conducted to investigate the antioxidant contents and activities of twelve vegetable sprouts (broccoli, red radish, radish, mizuna, kale, taatsai, pak choi, Chinese cabbage, turnip, rapeseed, chicory, and alfalfa). The total flavonoid contents of the broccoli, red radish, and radish sprout were $25.36{\pm}0.13$, $25.26{\pm}1.80$, and $25.16{\pm}1.25mg$ CE/100 g FW, respectively, and were significantly higher than those of the other tested vegetables. Radish sprouts had the highest total phenolic content (112.42 mg GAE/100 g FW), followed by red radish and broccoli sprouts. The main polyphenols in the vegetable sprouts were epicatechin and chlorogenic acid, but they varied across sprout varieties. The correlation between total flavonoids and total phenolics for the 12 vegetable sprouts was very high (r=0.926). The total antioxidant activity (DPPH and ABTS radical scavenging activities) was also highly correlated with total flavonoids and total phenolics.

• The Korean Journal of Food And Nutrition
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• v.34 no.6
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• pp.662-668
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• 2021

Aster koraiensis Nakai (A. koraiensis) which has been used as a food and medicinal plant in the past, is valuable as functional food material. Therefore, the aim of this study was to determine the antioxidant properties and major phenolics of A. koraiensis extracts with different ethanol concentrations (0, 50, 70, and 100% aqueous ethanol solution). When ethanol concentration in the extraction solvent was increased, extraction yield decreased; 34.2, 23.2, 21.0, and 5.5% in 0, 50, 70, and 100% ethanolic extracts, respectively. Total phenolics content and antioxidant activities of extracts were increased in an ethanol concentration-dependant manner. The major phenolics in the extracts were chlorogenic acid (21.264~58.666 mg/g), isochlorogenic acid A (10.432~145.353 mg/g), and isochlorogenic acid C(0.239~13.148 mg/g), and these phenolic contents were higher in 70 and 100% ethanolic extracts than other extracts. Significant correlations were observed between ethanol concentration of extraction solvent, antioxidant properties, and major phenolics. These results indicated that the optimal ethanol concentration for extraction was 70%.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.60-67
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• 2013

A laboratory experiment was conducted to determine the content of phenolics and flavonoids, antioxidant activity and antioxidant enzyme activity for the extracts from cowpea seed and sprouts. Plant length and weight of cowpea sprouts were significantly increased until 7 days after seeding. Total phenolics level [mg chlorogenic acid equivalents (CAE) $kg^{-1}$ DW] was highest in dry seed (DS) extracts of cowpea ($63.9mg\;kg^{-1}$), followed by imbibed seed (IS) ($56.8mg\;kg^{-1}$) and 1-day-old sprout (1DOS) extracts ($46.4mg\;kg^{-1}$), and significantly reduced with increase of sprout age (p < 0.05). The antioxidant activity of the methanol extracts from all the samples showed same tendency to the results of total phenolics level, and dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in DS (87.3%) and IS (41.2%) than in cowpea sprouts from 1DOS to 7DOS, ranging from 17.1 to 30.4%. Antioxidant enzymes, APX, POX, and POX activities were highest in 7DOS and lowest in DS. SOD activity showed much higher activity in sprouts and in seeds. Correlation coefficient between physiological-active substance and the activity was highest between APX and CAT activities ($r^2$= 0.9574). Especially, total phenolics content was more highly correlated with antioxidant or with antioxidant enzyme activities than was total flavonoid level.

• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.351-357
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• 2015

The aims of this study were to develop $macaron{\grave{e}}$ with Korean red pepper (Capsicum annuum L.) and GABA (${\gamma}$-aminobutyric acid) rice powder and analyze their physico-chemical and physiological characteristics. Korean red pepper (Capsicum annuum L.) was added to $macaron{\grave{e}}$ at a weight percentage of 0, 2.5 and 4.5%. Color values (L-value, redness, and yellowness), total sugar content, total phenolics, total carotenoids, ABTS radical scavenging activity, textures, and sensory characteristics with varying various Korean red pepper were measured. As the ratio of the powders in the $macaron{\grave{e}}s$ increased, total phenolic content, total carotenoid content, and radical scavenging activity increased. There were significant differences in total phenolic and total carotenoid content of $macaron{\grave{e}}s$ (p<0.05). Sensory evaluation indicated significant differences (p<0.05) in color, sweetness, texture, and overall acceptability depending on the addition of Korean red pepper. KR30 $macaron{\grave{e}}$, showed higher overall acceptability, as compared to other $macaron{\grave{e}}$.

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.04a
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• pp.137-137
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• 2021

The study of total phenol (TP) content from 700 rice varieties was evaluated using the UV-Vis spectrophotometric method. The calibration curve of serial diluted gallic acid as a standard of this study showed the acceptable performances (R² = 0.999, mean accuracy 90%) and the mean of % relative standard deviation (%RSD: 0.07%) within the range of 7.8 to 1000 ppm concentrations. The mean value of total phenol content from 700 rice varieties was 2723.15 ㎍/g ranged from 55.48 ㎍/g to 9922.23 ㎍/g and the mean %RSD was 2.5%. Furthermore, this study aim was to analyze and profile individual phenolic compounds in the rice genetic resources to construct an integrative database for development of new rice variety with high functionality for health and understanding of phenolics characteristics in the rice grain. Herein, we analyzed selected 100 rice varieties based on high TP content and identified total 15 phenolic compounds by LC-ESI-MS/MS. Among selected 100 rice genetic resources, the phenolic metabolites consisted of higher amount of flavonoid (catechin) and phenolic acid mainly protocatechuic acid. Further research of more selected rice genetic resources would be continued to provide for an integrative phenolics profile of different rice genetic resources.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.1
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• pp.51-59
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• 2012

Contents of phenolics and flavonoids, antioxidant activity and cytotoxicity were investigated in the methanol extracts of three different $Taraxacum$ species, $Taraxacum$ $coreanum$, $Taraxacum$ $mongolicum$, and $Taraxacum$ $officinale$. Total phenolics content at $1000mg\;kg^{-1}$ was more present in shoot parts than in roots, and was highest in $T.$ $mongolicum$ shoot and root extracts (76.8 and $40.0mg\;kg^{-1}$, respectively), followed by $T.$ $coreanum$ and $T.$ $officinale$ ($p$ < 0.05). Total flavonoid level had same tendency to total phenolics among $Taraxacum$ species, showing lower amounts ($6.5{\sim}36.4mg\;kg^{-1}$) than total phenolics. The antioxidant activity of the methanol extracts from all the species dose-dependently increased. DPPH free radical scavenging activity at $1,000mg\;kg^{-1}$ was highest in shoot and root extracts from $T.$ $mongolicum$ by 89.6 and 83.4%, respectively. According to MTT assay, cell viability of Calu-6 (human pulmonary carcinoma) was lowest in the $T.$ $mongolicum$ shoot and root extracts ($IC_{50}$ values=83.4 and $66.4mg\;kg^{-1}$, respectively), and followed by $T.$ $coreanum$ and $T.$ $officinale$ (lowest). Calu-6 was more sensitive to the extracts than SNU-601 (human gastric carcinoma). Antioxidative and anticancer activities in three different $Taraxacum$ species was more correlated with total phenolics content ($r^2$=0.0097 to 0.6213) than with total flavonoids level ($r^2$=0.0027 to 0.4627). The results showed total phenolics content and total flavonoids level were highly correlated with anticancer activity and antioxidant activity, and their content and activities were different depending on species.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.183-191
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• 2014

BACKGROUND/OBJECTIVES: The objective of this study was to measure and/or estimate the total antioxidant capacity of the Korean diet. MATERIALS/METHODS: Eighty-one plant foods that were expected to exhibit rather high antioxidant activities were selected from the Korean diet using the Fifth Korean National Health and Nutrition Survey (KNHANES V). These foods were categorized into 11 food groups: cereals, potatoes, legumes, nuts, vegetables, kimchies, mushrooms, fruits, fruit juices, sea weeds, and oils. The foods were mixed in the proportions specified in traditional Korean recipes and analyzed. The measured indicators for antioxidant capacities were total phenolics, 2,2-diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC). RESULTS: Total phenolics were high in the fruit juices, nuts, vegetables, and fruits; and the average DPPH, ORAC, and TEAC values were high in the vegetables, fruits, fruit juices, and nuts. The correlation coefficient between the content of total phenolics of each food and the in vitro antioxidant capacity was relatively high at 0.851. The intake of total phenolics per capita per day in the Republic of Korea was estimated to be 127 mg. The total dietary antioxidant capacity (TDAC) values, which were obtained from the total antioxidant capacity of each food, taking into account the intake of each food, were 20,763, 54,335, and $876.4{\mu}mol$ of Trolox equivalents using the DPPH, ORAC, and TEAC methods, respectively. The food group that contributed the most to the Korean TDAC was cereals at 39.7%, followed by fruits and vegetables at 27.8% and 13.9%, respectively. The contribution of legumes, nuts, fruit juices, and mushrooms was quite minimal at less than 2% each. CONCLUSIONS: The content of total phenolics and the antioxidant capacity of the Korean diet are significantly correlated and the high contributing food groups are cereals, fruits, and vegetables.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.13-19
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• 2013

This study was carried out to find the optimal conditions for red cabbage seed sprouts in terms of their physicochemical and sensory qualities by electron-beam irradiation, cultivation and storage using the response surface methodology (RSM). Moisture content ($R^2$=0.9638) was affected by irradiation dose and cultivation time. Total phenolics content ($R^2$=0.9117) was mainly affected by irradiation dose, but carotenoid content ($R^2$=0.8338) was affected in the order of irradiation dose, cultivation time and storage time. Sensory properties were also affected by irradiation dose, and thus scores decreased as irradiation dose increased. The optimum conditions estimated by superimposing total phenolics content and overall acceptance were 2.2-3.8 kGy of the irradiation dose, 3.0-4.0 days of cultivation and 2.0-3.0 days of storage.