• Korean journal of food and cookery science
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• v.15 no.1
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• pp.55-60
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• 1999

Free phenolic acid, soluble phenolic acid ester and insoluble bound phenolic acid were extracted from defatted perilla flour. Their antioxidative effects were compared with those of BHA, AE and TBHQ for soybean oils by measuring acid and peroxide values at 60$^{\circ}C$ for 25 days. The patterns of these extracts were compared by using gas chromatography. Free phenolic acid and soluble phenolic acid ester extracts showed a higher antioxidative effects than BHA and AP. Among phenolic extracts, free phenolic acid showed the most effective antioxidant activity in soybean oil. Six types of free phenolic acid, 3 types of soluble phenolic acid ester, and 2 types of insoluble phenolic acid were found in the extract.

• Journal of the Korean Society of Food Culture
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• v.14 no.1
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• pp.43-48
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• 1999

The antioxidative effects of phenolic acids extracts from defatted sesame meal were investigated on the soybean oil. The free, ester and insoluble bound phenolic acids in the extracts from defatted sesame meal were isolated and their antioxidative activities were evaluated with commercial synthetic antioxidants such as BHA, AP and TBHQ. The patterns of these extracts were compared by using gas chromatography. Ether extracts from the defatted sesame meal showed a higher antioxidative effectiveness than BHA and AP. Among phenolic extracts, free phenolic acid and soluble phenolic acid ester were found most effective in the sesame meal. Each phenolic extract was confirmed to be composed of six or three individual compounds.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.721-726
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• 1996

Fatty acid composition and phenolic acid content of rice with different milling fractions were analyzed to provide basic data for nutrition, processing and storage of rice. Major fatty acids of rice were palmitic, oleic and linoleic acids and their respective contents were 20.0%, 33.3% and 43.0% of embryo, 17.3%, 45.1% and 34.5% of rice bran and 23.4%, 26.2% and 46.1% of milled rice. Outer fraction had a high content of oleic acid but a low content of linoleic acid in rice bran. As milling yields increased in milled rice, oleic acid content increased, but palmitic acid, linoleic acid, stearic acid and linolenic acid contents decreased. Contents of free, esterified and insoluble bound phenolic acid extracts from bran were 321.0mg%, 299.7mg% and 212.4mg%, respectively. Milled rice contained 118.0mg% of free phenolic acids, 56.0mg% of insoluble bound phenolic acids and no esterified phenolic acids. Rice bran contained 86.2% of ferulic acid as a principal phenolic acid. It also contained 35.7~36.6% of sinapic and syringic acids, 16.7% of p-coumaric acid and 0.13% of vanillic acid as minor component. Contents of total phenolic acid, expressed in terms of tannic acid, among rice with different milling fractions was highest in embryo. It was higher in outer fraction in bran, but rarely detected as fractionation of the component with milling in milled rice.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.9-14
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• 1993

The free, ester and insoluble bound phenolic acids in the extracts from defatted perilla seed flour were isolated and their antioxidative activities were evaluated in comparison with commercial synthetic antioxidants. Total phenolic content of the perilla seed was 0.75% as chlorogenic acid. Each percent ratio of the content of free, ester, and insoluble bound phenolic acid to total phenolic content was 87.5, 7.5 and 5.0% respectively. Chlorogenic acid was identified as a major phenolic acid and a small amount of caffeic acid was also identified in the free phenolic acid extract, but they were not found in soluble ester and insoluble bound phenolic extracts by two dimensional paper chromatography. Each type phenolic extract from 30g of deffated perilla flour showed antioxidant activity similar to that of BHT (0.02%, w/w) in 200g of soybean oil substrate inspite of the difference of each phenolic content.

• Journal of Ginseng Research
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• v.30 no.1
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• pp.22-30
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• 2006

Phenolic acids of white ginseng were extracted and fractionated into free, esterified, and insoluble-bound forms. The contents of individual phenolic acids in different forms were quantified by gas liquid chromatography. Nine different phenolic acids as free, esterified, and insoluble-bound forms were identified in white ginseng. Total phenolic compounds in different forms of extracts was 0.309% (free form), 0.230% (esterified form) and 0.138% (insoluble-bound form), respectively. Total phenolic acid contents in free, esterified and insoluble-bound form were 889.3, 356.8, 1,176.9 mg/100g fraction, respectively. Ferulic acid was the predominant phenolic acid, representing 63.7% and 50.9% of total phenolic acids in esterified fom and insoluble-bound form, respectively. While caffeic acid was only detected in esterified form. At 10 mg/ml insoluble-bound form quenched 95.9% ABTS free radicals generated from 2,2-azobis(2-amidinopropane) dihydrochloride (AAPH). Also, electron donating ability and lipid peroxidation inhibitory activity of insoluble-bound fom were higher than other fraction. All phenolic acid fractions scavenged over 80% of hydroxyl radical at 10 mg/ml.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.593-597
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• 2010

This study investigated the properties and antioxidative activities of phenolic acid concentrates of rice bran. Rice bran contains bioactive substances such as phenolic compounds, which can provide health benefits as natural antioxidants. This study examined how levels of phenolic acids can be obtained efficiently through various extraction methods. The extractions of defatted rice bran were followed by using ethylacetate (RBE-I), ethylacetate after alkaline hydrolysis (RBE-II), and 80% methanol (RBE-III). For all extracts, yields (%), total polyphenol contents (TPC), various phenolic acids and antioxidative activities were estimated. RBE-II had the highest total polyphenol contents (526.72 mg/100 g rice bran) and showed high antioxidative activity (74.7%). To concentrate the phenolic acids, RBE-II was passed through Sep-pak $C_{18}$ Vac cartridge and F1-RBE-II was collected by the elution of 50% methanol. The total phenolic content of F1-RBE-II (736.8 mg/100 g rice bran) was higher than that of RBE-II (367.1 mg/100 g rice bran), and the ratios of ferulic acid (73%) and sinapic acid (14%) increased. As RBE-II was analysed by HPLC, 6 different phenolic acids were found via chromatography, whereas F1-RBE-II showed 5 different peaks and the major phenolic acid was identified as ferulic acid. The ABTS radical scavenging activity of F1-RBE-II was the highest among the rice bran extracts. In a ${\beta}$-carotene-linoleic acid model system, linoleic acid oxidation was reduced by F1-RBE-II (73%) and RBE-II (35%).

• Journal of Ginseng Research
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• v.31 no.4
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• pp.230-236
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• 2007

This study was conducted to investigate the contents of the total phenolic compounds, and DPPH, ABTS radical scavenging activities of phenolic acid fractions of ginseng according to steaming times. Also the individual phenolic acid compositions and contents were analyzed by GC. The contents of the total phenolic compounds proportionally increased from 0.530 to 2.893% according to steaming times. Phenolic acid fractions were separated according to bound types, and the insoluble bound form fraction showed the highest contents followed by ester form fraction and free form fraction. The total contents of these three fractions (1.031-1.416%) were not significantly influenced by steaming times. Salicylic, cinamic, p-hydroxybenzoic, gentisic, vanillic, syringic, caffeic, ferolic acid were found in each fraction, and gentisic and ferolic acid were the major phenolic acid. Each phenolic acid fraction showed over 50% of DPPH and ABTS radical scavenging activities. There were no differences between the phenolic acid fractions according to binding types. Free radical scavenging activities were affected by a number of steaming times and augmented as steaming times increased.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.162-167
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• 2002

Free, soluble esterified and insoluble bounded phenolic acids were separated from Eungi chestnut endoderm. The composition and contents of phenolic acid were analyzed by gas chromatography, and their antioxidant activity was examined by DPPH assay, 2-deoxyribose oxidation, and ferric thiocyanate method. Gallic, ellagic, salicylic, and gentisic acids in free phenolic acid fraction, gallic, ellagic, and protocatechuic acids in soluble esterified fraction, sianpic and gentisic acids were the major phenolic acids in insoluble bounded fraction. Marked differences were observed in the phenolic acid composition and contents among the fractions. Free phenolic acid fraction showed the strongest antioxidant activity. Results revealed chestnut endoderm could be a potential antioxidant source containing gallic and ellagic acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.17-22
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• 1992

Water extract, and free-, ester- and insoluble phenolic acids were extracted from wormwoods. The extracts were then dissolved in equal amounts of an edible soybean oil, and the resulting substrates, portion of the soybean oil (control), 0.02% BHA and 0.02% BHT were stored in incubator at $45^{\circ}C{\pm}1.0^{\circ}C$ for 32days. Peroxide values (POV) and thiobarbituric acid (TBA) values of control and the substrates were determined during th9 storage period. The POV of control, BHA, BHT and six substrates which were contained water extracts 0.5%, 1% and 1.5%, and free-, ester- and insoluble phenolic acids after 24days of storage were 77, 43, 17, 38, 26, 34, 45, 28 and 16m mole/kg oil respectively, The TBA values after 32days of storage were 0.278, 0.170, 0.070, 0.200, 0.178, 0.235, 0.167, 0.136, 0.062, respectively, It was found that the antioxidant activity in water extracts was highest in water 1 (the substrates containing water extracts 1%). It was also found that antioxidant activities in the phenolic acids were decreased in the following order ; insoluble phenolic acids>ester form>free phenolic acids. The phenolic acids separated and tentatively identified by Gas chromatography were catechol, vanillin, umbelliferone, p-coumaric acid, ferulic acid caffeic acid, protocatechuic acid, p-hydroxy benzoic acid and syringic acid.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.239-243
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• 1993

Chemical structures of phenolic antioxidative components of defatted Terminalia chebula R. were elucidated by used MS and H-NMR. The results showed that the phenolic antioxidative components were identified as ferulic acid, vanillic acid, p-coumaric acid in free-acid extracts, and caffecic acid, vanillic acid and p-coumaric acid in soluble-acid extracts, and caffeic acid, phloroglucinol and pyrogallol in insoluble-bound extracts, respectively.