• Food Science and Biotechnology
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• 제17권2호
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• pp.251-256
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• 2008

Changes in antioxidant activity of Rubus coreanus fruit of 3 clones (S13, S114, and S16), which were selected from different sites, were studied at different ripening stages. Antioxidant activities (tree radical scavenging activity and reducing power) were determined and their relationships to total phenolic contents and ascorbic acid were analyzed. The highest tree radical scavenging activities of 3 clones (S13, S14, and S16) were 79.39, 75.80, and 81.16% at $125\;{\mu}g/mL$, respectively. In general, the antioxidant activity and the related parameters, including total phenolic content and vitamin C content decreased during fruit ripening. Total phenolic contents of the R. coreanus fruits (S13, S14, and S16) were correlated with tree radical scavenging activity ($R^2=0.8114$, 0.9186, and 0.9714). These results improve knowledge of the effect of ripening on the antioxidant activity and related compounds contents that could help to establish the optimum R. coreanus fruit harvest data for various usages.

• 한국식품과학회지
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• 제49권3호
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• pp.338-342
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• 2017

The antioxidant activities of sesame cake extracts prepared using ethanol and hot water were evaluated. Seventy percent-ethanol extracts yielded the highest total phenolic (96.56 mg/g extract) and flavonoid (8.35 mg/g extract) contents. In the ${\beta}$-carotene bleaching and ferric thiocyanate test, 30%-, 50%-, and 70%-ethanol extracts exhibited higher antioxidant activity than that exhibited by 90%-ethanol extracts. However, 90%-ethanol extracts showed greater antioxidant activities in phenyl-2-picryl-hydrazyl free radical scavenging test and thiobarbituric acid test using corn oil. The antioxidant activities of sesame cake extracts did not correlate with the total phenolic and flavonoid contents; however, the results suggest that oxidative stability may be improved by sesame cake extracts.

• Preventive Nutrition and Food Science
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• 제19권3호
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• pp.204-212
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• 2014

The bioactive compounds and antioxidant activity of aronia leaves at different stages of maturity were identified and evaluated. Young and old leaves were approximately 2 months of age and 4 months of age, respectively. The young leaves contained more polyphenols and flavonoids than the old leaves. Three phenolic compounds (i.e., chlorogenic acid, p-coumaric acid, and rutin) were detected by HPLC. Antioxidant activity was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical, and superoxide anion radical scavenging assays. The reducing power of aronia leaf extracts increased in a concentration-dependent manner ($0{\sim}100{\mu}g/mL$). The antioxidant activity of the 80% ethanol extract was greater than that of distilled water extract. The high phenolic compound content indicated that these compounds contribute to antioxidant activity. The overall results indicate that aronia leaves contain bioactive compounds, and that younger aronia leaves may be more favorable for extracting antioxidative ingredients because they contain more polyphenols.

• Food Science and Biotechnology
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• 제16권1호
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• pp.55-61
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• 2007

The antioxidant activities of water, ethanol, methanol, and chloroform extracts of Ulmus davidiana were evaluated using various antioxidant assays: DPPH (1,1-diphenyl-2-pricrylhydrazyl) free radical scavenging; hydroxyl radical scavenging; lipid peroxidation scavenging; and reducing power assays. All extracts, except the chloroform extract, demonstrated strong antioxidant activity in all assays. The chloroform extract had the highest hydroxyl radical scavenging activity, and its activity was equivalent to $\alpha$-tocopherol at a concentration of 0.5 mg/mL. Additionally, the antidiabetic activity of their extracts was also evaluated using a rat intestinal $\alpha$-glucosidase inhibition assay. Among all extracts investigated, the methanol extract had the highest $\alpha$-glucosidase inhibitory activity, although its activity was less than acarbose at $0.5\;{\mu}g/mL$. This result suggested that U. davidiana extracts may have antidiabetic activity. Total phenolic compounds and flavonoids were also measured. Phenolic compounds such as tannic acid, p-coumatric acid, and kaempferol were detected by high-performance liquid chromatography (HPLC). These results suggest that U. davidiana extracts may be useful as a potential source of antioxidant and antidiabetic materials.

• Journal of Applied Biological Chemistry
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• 제65권2호
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• pp.89-92
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• 2022

In this study, the effects of soil conditions on antioxidant activities of the aerial and underground parts of rosemary were assessed to determine the most effective soil conditions for cultivation. The antioxidant activity was the highest (51.58±2.93 ㎍/mL) when cultivated in the mixture of gardening soil and vermiculite using DPPH assay. The antioxidant activity of underground parts the highest (127.48±12.38 ㎍/mL) when cultivated in the mixture of soil, vermiculite, and perlite. ABTS assay showed that the antioxidant activity of aerial parts was 230.34±57.93 ㎍·mL^-1 when cultivated in the mixture of gardening soil and vermiculite and that of underground parts was 320.98±16.04 ㎍·mL^-1 when cultivated in the mixture of gardening soil, vermiculite, and perlite. The total phenolic content of aerial parts was the highest (155.25±2.96 mg GAE/g) when cultivated in the mixture of gardening soil. The total flavonoid content of aerial parts was the highest (67.32±5.27 mg QE/g) when cultivated in the mixture of gardening soil. Therefore, the mixture of gardening soil, vermiculite, and perlite is superior to gardening soil alone for cultivation of rosemary to increase its antioxidant activity as well as total phenolic and flavonoid content.

• Journal of Ginseng Research
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• 제34권3호
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• pp.198-204
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• 2010

Korean ginseng (Panax ginseng C.A. Meyer) preserved in syrup, known as ginseng Jung Kwa (GJK), is a popular traditional snack in Korea. We investigated the effects of heat processing time on total phenolic content and antioxidant capacity of GJK. Water extract was prepared from GJK with different heat processing times, 3 hours (GJK-3), 6 hours (GJK-6), or 12 hours (GJK-12), with sonication for 2 hours. The GJK extract contained total phenolic content in the following order: GJK-12 (2.28%)>GJK-6 (1.57%)>GJK-3 (1.29%). Both the peroxy and hydroxyl radical-scavenging activity and cellular antioxidant capacity of GJK extract was significantly enhanced with increasing heat processing time. The hydroxyl radical-scavenging activity of GJK-12 extract was greater than that of the GJK-3 and GJK-6 extracts, consistent with metal chelating capacity and reducing capacity. In a cellular model, the GJK extract effectively reduced 2,2'-azobis(2-amidinopropane) dihydrochloride, $Cu^{2+}$-, and $H_2O_2$-induced oxidative stress, with GJK-12 and GJK-6 extracts demonstrating greater cellular antioxidant capacity than the GJK-3 extract. These results suggest that heat processing time can contribute to the antioxidant capacity of GJK and that GJK extract may have the potential to be used as an effective dietary antioxidant to prevent oxidative stress-related diseases.

• Journal of Applied Biological Chemistry
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• 제62권2호
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• pp.195-202
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• 2019

붉나무(Rhus javanica L.)는 동아시아에서 주로 분포하는 옻나무과의 식물이다. 붉나무의 잎, 줄기, 뿌리 에틸아세테이트 분획물의 항산화 활성 및 항염증 활성을 확인하였다. 붉나무 뿌리 에틸아세테이트 분획물의 DPPH 및 ABTS radical 소거활성이 가장 효과적이었으며, 총 페놀 화합물의 함량은 62.9, 70.3, 73.9 mg/g으로 나타났다. HPLC/PDA 분석을 통해 gallic acid를 동정 및 정량하였다. LPS로 자극시킨 RAW264.7 세포에서 항염증 활성을 확인하였다. iNOS의 발현 억제를 통한 NO 생성을 억제하였으며, 이러한 결과들을 통해 gallic acid를 포함하고 있는 붉나무는 염증 질환의 효과적인 경감 및 치료제로 개발될 수 있는 가능성을 보였으며, 붉나무 뿌리의 에틸아세테이트 분획물의 활성이 잎과 줄기 에틸아세테이트 분획물의 활성보다 뛰어났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.264-267
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• 2005

The purpose of this study was to investigate the ultra sonic extraction method of phenolic compounds and antioxidant activity from Rumex crispus. Rumex crispus was fractionated with hexane, ethyl acetate, butanol and water. The amount of phenol compounds and antioxidant activity was presented higher content in ethyl acetate fraction then others.

• Preventive Nutrition and Food Science
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• 제12권3호
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• pp.173-176
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• 2007

${\gamma}-Oryzanol$ is one of the chain breaking antioxidants. Both sterol (triterpene) and phenolic hydroxyl groups in the structure of ${\gamma}-oryzanol$ may be responsible for its antioxidative function. We hypothesize that ${\gamma}-oryzanol$ is more effective in preventing the autoxidation of polyunsaturated fatty acid (PUFA) than the synthetic phenolic compounds in an oil/water (O/W) emulsion system. The antioxidative effectiveness of different concentrations of ${\gamma}-oryzanol$ and synthetic antioxidants was evaluated at different incubation times (0, 4, 8, 16, and 32 h) by measuring both the formation of hydroperoxides and the decomposition product of hydroperoxides (hexanal) in each emulsion system. Overall, the order of effectiveness of various antioxidants for inhibiting the formation of hydroperoxide in the O/W emulsion was: ${\gamma}-oryzanol$> tert-butylhydroquinone (TBHQ)> butylated hydroxytoluene (BHT)> butylated hydroxyanisole (BHA). O/W emulsion with selective lower concentrations of ${\gamma}-oryzanol$ showed better effectiveness than that with higher concentration of synthetic antioxidants. However, the ability of both ${\gamma}-oryzanol$ and synthetic antioxidants to decompose hydroperoxide was similar. ${\gamma}-Oryzanol$ was more effective antioxidant than the synthetic phenolic compounds in preventing the formation of hydroperoxide in the O/W emulsion system.

• Food Science and Biotechnology
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• 제15권1호
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• pp.44-50
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• 2006

Contents of phenolic compounds in peel, flesh, and core of three Asian pear cultivars, Hosui, Niitaka, and Chuwhangbae, were determined at different stages of maturity. Antioxidant properties of methanol extracts of peels at various fruit maturity stages were also evaluated. Total phenolic content decreased with maturity. Arbutin, chlorogenic acid, and epicatechin were major phenolic compounds in young fruits. Catechin, 4-hydroxymethyl benzoic acid, and caffeic acid were detected in peel and core of immature and mature pears. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of methanol extracts were 16.30 and $15.73\;{\mu}g$ in peel of immature Hosui and Chuwhangbae pears, respectively, and $11.59\;{\mu}g$ in mature Niitaka pears, which was significantly higher than those of other maturity stage in the same cultivar. Inhibitory activities on lipid oxidation of methanol extracts of three cultivars at all maturity stages were similar to that of ${\alpha}$-tocopherol.