• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.80-89
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• 2019

Pine barks are important biomass resources because they are utilised in the production of pine wood and rosins. However, no chemical study has been conducted on the hydrophilic status of pine barks in Indonesia. This aim of this study is to explore the hydrophilic extracts of the barks from six Pinus species (P. elliotii, P. caribeae, P. oocarpa, P. merkusii P. montezumae, and P. insularis). The hydrophilics of pine barks were analysed using gas chromatography-mass spectrometry. The presence of polyphenol contents in the ethanol extracts obtained from the barks of six Pinus species was determined using the tannin-formaldehyde method, Folin-Cioucalteu assay, and vanillin-HCl assay. The ethanol and hot water soluble extractives derived from inner barks were higher in quantity when compared to those derived from the outer bark samples. The polyphenol measurement showed that the highest value of total phenol content was derived from the outer bark of P. montezumae whereas those of the total phenol and tannin- formaldehyde contents were derived from the inner and outer barks of P. oocarpa. GC-MS analysis revealed that nitrogenous compounds are dominant constituents in the inner and outer barks of the six species, followed by sugars and monophenolics, respectively.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.228-234
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• 2022

Various types of tea have been cultivated to obtain different flavors and enhance their functional properties. The objective of this study was to investigate the physicochemical properties of γ-aminobutyric acid (GABA) teas produced from commercial Korean green, white, and black teas. The concentration of total minerals was reduced in GABA green tea and GABA white tea but was improved in GABA black tea. The essential, non-essential, and total free amino acid contents were remarkably increased in the GABA teas. The amino acid GABA content was increased by 561.00 and 294.20 times in GABA white tea and GABA black tea, respectively. The antioxidant potential was not reduced, although the total polyphenol and total flavonoid contents decreased in GABA green tea and GABA black tea. The results indicated that the overall nutritional value of commercial green, white, and black teas could be improved by processing them into GABA teas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.4
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• pp.499-502
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• 2007

The objective of this study was to determine antioxidant compounds in specialty rice including milled rice, brown rice, red rice, giant embryonic rice, black rice, green rice, and Goami consumed in Korea. The concentrations of total polyphenols (insoluble and soluble polyphenols), phytic acid, and anthocyanin in the samples were measured using spectrophotometric methods and vitamin I analysis was carried out by HPLC. The contents of the total polyphenolic compounds were 565mg/100g for black rice, 405mg/100g for red rice, 140mg/100g for giant embryo rice, 138mg/100g for Goami, 133mg/100g for brown rice, 127mg/100g for green rice, and 66mg/100g for white rice. The black and red rices were significantly high in polyphenolic contents compared with the other rices, apparently due to their intense red-purple color. Black rice, red rice, and Goami showed significantly higher vitamin E and phytic acid contents compared with other rices. Anthocyanins were determined in only black rice (302mg/100g) due to the detection limits of spectrophotometric assay. hlthough vitamin I and anthocyanin contents were relatively lower than polyphenolics among the samples, the specialty rice may contribute to the significant supply of antioxidant compounds to prevent oxidative stress due to the fact that rice is used as a staple food and consumed in large amounts in our diets. The results can be used to increase rice consumption by enhancing consumer awareness on health benefits of the rice.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.355-360
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• 2011

This study was performed to investigate the antioxidant effects of 4 citrus fruits including Hallabong, Cheonhyehyang, Cheonggyeon, and Jinjihyang. In this study the citrus fruits were separated in three parts of peel, pulp segment membrane (PSM), and pulp and extracted with methanol, then concentrated using a rotary vacuum evaporator. Total polyphenol contents ranged 23.497~42.341 mg/g in peel, 13.285~21.872 mg/g in PSM and 6.333~11.627 mg/g in pulp of the citrus fruits. The total polyphenol contents were highest in the peel and PSM of Jinjihyang and in the pulp of Cheonhyehyang. 1,1-diphenyl-2picryl hydrazyl (DPPH) radical scavenging activities were highest in the peel and PSM of Jinjihyang and in the pulp of Cheonhyehyang. 2,2'-Azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacities were also highest in the peel and PSM of Jinjihyang and in the pulp of Cheonhyehyang. Reducing powers were highest in the peel of Cheonggyeon, in the PSM of Jinjihyang, and in the pulp of Cheonhyehyang. There were significant correlations in between total polyphenol contents and the radical scavenging activities, and reducing power each other. These results indicate that the 4 citrus fruits (Hallabong, Cheonhyehyang, Cheonggyeon, and Jinjihyang) evidently have antioxidant capacities and their peel parts have the highest antioxidant activities.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.775-782
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• 2018

The purpose of this study was to investigate effects of Crataegus pinnatifida var. psilosa extracts obtained from 95% methanol and water. Methylene chloride, ethyl acetate, and methanol were used to fractionate the 95% methanol extract and each fraction was testified total polyphenol contents, electron donating abilities, the scavenging abilities of superoxide anion radical, as well as hydrogen peroxide. Extraction yields of 95% methanol and water from Crataegus pinnatifida var. psilosa were 25.40%, 23.12% respectively. Total polyphenol contents were $28,708.0{\pm}1,755.05{\mu}g\;GAE/mL$ in 95% methanol, revealing the highest among them, $12,726.67{\pm}479.33{\mu}g\;GAE/mL$ in water extract, $15,854.67{\pm}498.38{\mu}g\;GAE/mL$ in methanol fraction, $11,810.67{\pm}584.48{\mu}g\;GAE/mL$ in ethyl acetate fraction, and $5294.67{\pm}190.36{\mu}g\;GAE/mL$ in methylene chloride fraction. Total polyphenol contents revealed significant differences (p<0.05) between the solvents. In the experiment of the electron donating ability, water extract revealed $84.33{\pm}0.1%$ scavenging ability, the highest. Other extracts and fractions were $81.8{\pm}1.11%$ for water, $79.73{\pm}1.32%$ for ethyl acetate fraction, $75.73{\pm}2.17%$ for methylene chloride fraction, and $42.1{\pm}5.01%$ for methanol fraction, the lowest electron donating ability. Electron donating abilities revealed significant difference (p<0.05) between the solvents. In the experiment of superoxide anion radical scavenging ability, ethyl acetate fraction($0.0026{\pm}0.0002$) had the highest scavenging ability, and the others revealed slight increase rather than decrease in scavenging ability. Hydrogen peroxide scavenging ability revealed the highest in methanol fraction ($-0.00206{\pm}0.00165$) and the others were as follow; water extract ($0.00157{\pm}0.00249$), 95.0% methanol extract ($0.005{\pm}0.0036$), methylene chloride fraction ($0.0039{\pm}0.00364$), and ethyl acetate fraction ($0.0002{\pm}0.00059$).

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.147-152
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• 1999

HPLC was used for determining polyphenols which are known as the functional compounds in the unripe apples Fuji and Aori. The changes in their contents caused by heat treatments were monitored. The carbohydrate contents in Fuji and Aori were 14.1% and 13.5% respectively. Both apple juices showed pH 3.2 and $8.0\;brix^{\circ}$, which were relatively low levels. The major polyphenols were composed of (+)-catechin, chlorogenic acid, (-)-epicatechin, and tannic acid. Total polyphenol contents in Fuji and Aori were 0.11, 0.12% by Folin-Denis method. HPLC analysis of polyphenols showed that four major components were contained by 0.06% in Fuji and 0.07% in Aori. Chlorogenic acid was three times higher in Fuji than in Aori. After water blanching, the area percent of polyphenols resulted in an increase by 3.54% in Fuji but a decrease by 2.93% in Aori. Pasteurization of juices led to decrease by 1.39% and 3.31% respectively. Blanching and pasteurization of unripe apple juices induced negligible changes in polyphenol contents during storage. During concentration, polyphenol contents increased in proportion to the concentration of unripe apple juices.

• The Korean Journal of Community Living Science
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• v.27 no.4
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• pp.851-862
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• 2016

This study was conducted to investigate the proximate composition and antioxidative activities of young barley leaf(YBL). YBL powder(all w/w) was 2.98% moisture, 17.13% crude protein, 4.00% crude fat, 10.72% crude ash, and 65.17% carbohydrate. The contents of total, insoluble, and soluble dietary fiber were $36.62{\pm}2.33$, $19.05{\pm}1.04$, and $17.57{\pm}1.01g/100g$, respectively. The essential and non-essential amino acids contained in the YBL powder accounted for 46.56% and 53.44% of the total amino acids, respectively. The major unsaturated fatty acid was linolenic acid. The ratio of polyunsaturated fatty acids to saturated fatty acids was 4.84. Only tartaric acid was detected. The contents of vitamins A, C, and E were 0.761, 398.05, and 0.936 mg%, respectively. The mineral contents of YBL powder were in the order of Na$IC_{50}$ value for the DPPH radical scavenging of the YBL ethanol extract was $365.74{\pm}6.98mg/mL$. The antioxidative index was high and was similar to that of t-butylated hydroxytouene. These results suggest that YBL can be recommended as a baby vegetable of high nutritional quality and antioxidative properties.

• The Korean Journal of Food And Nutrition
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• v.37 no.4
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• pp.189-196
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• 2024

To develop farm-made high effective vinegar, this study prepared apple vinegar using four kinds of acetic acid bacteria isolated from a natural fermentation liquid of 'Cheongsoo' grapes and analyzed vinegar samples fermented 93% apple juice and 7% alcohols at 30℃ for 20 days. To accomplish this, quality characteristics such as pH, total acidity, reducing sugar, organic acid, color, total polyphenol contents, and antioxidant activity contents were determined. The pH decreased while total acidity of all samples gradually increased during fermentation period. The vinegar with AP 21 strain tended to increase the total acidity quicker than other stains. Reduced sugar content remained high until the last fermentation day. Furthermore, reduced sugar contents of all vinegars increased as fermentation progressed by decomposing sucrose present in apples. When physiological activities were compared, apple vinegars fermented with AP 21 and 30 strains had higher total polyphenol and flavonoid contents than other samples. However, there was no significant difference in antioxidant activity between samples. These results indicate that strain 21 is the most suitable starter as acetic acid bacteria for producing farm-made vinegar.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.29-36
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• 2012

This study was conducted to investigate antioxidative and physiological activities of two stage fermented Chinese Yam (TSFCY) by Monascus sp. MK2 and Lactobacillus brevis HLJ59. The extracts from TSFCY were measured to examine pigments, monacolin K contents, total polyphenol and flavonoid contents, DPPH radical scavenging activity, reducing power, ACE inhibitory activity and GABA contents. In this study, the results show that Monascus sp. MK2 and Lactobacillus brevis HLJ59, with Dioscorea batatas Dence. As the substrate can produce pigments (yellow, orange and red), monacolin K contents, total polyphenol and flavonoid contents, DPPH radical scavenging activity, reducing power, ACE inhibitory activity, and GABA contents at 14.03 (yellow), 13.88 (orange), 15.71 (red), 487.9 (MK, mg/kg), 723.8 (TP, mg/kg), 326.4 (TF, mg/kg), 81.7 (DPPH, %), and 1.5 (RP, O.D), respectively. In addition, the showed ACE inhibitory activity and GABA contents was 86.9% and 977.4 mg/kg in EtOH extract, respectively.

• Journal of Plant Biotechnology
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• v.48 no.4
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• pp.264-270
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• 2021

In the present study, the total polyphenol and flavonoid contents, radical scavenging ability, and reducing power of ethanol extracts and fractions from Rubus coreanus Miq. were assessed in order to determine the antioxidant activity. The total polyphenol contents in the 70% ethanol extract and ethyl acetate fraction were 238.46 mg gallic acid equivalents (GAE)/g and 413.59 mg GAE/g, respectively; these values were higher than those in the other fractions (p < 0.05). In addition, the total flavonoid content was as high as 52.83 mg quercetin equivalents (QE)/g in the ethyl acetate fraction (p < 0.05). With regard to DPPH and ABTS radical scavenging activities, the RC₅₀ values of the ethyl acetate fraction were 3.95 and 6.25 ㎍/mL, respectively, indicating that the scavenging activity was similar to that of ascorbic acid (control) (p < 0.05). Moreover, in the FRAP assay performed to assess the reducing power, the ethyl acetate fraction showed high activity (p < 0.05). In summary, the present findings confirmed that the ethyl acetate fraction of the R. coreanus Miq. 70% ethanol extract had high polyphenol and flavonoid contents and excellent antioxidant properties. Therefore, it was confirmed that the ethyl acetate fraction of the mugwort 70% ethanol extract had high polyphenol and flavonoid content and excellent antioxidant effect.