• Preventive Nutrition and Food Science
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• 제18권1호
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• pp.80-84
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• 2013

This study was conducted to evaluate the increase of DPPH radical scavenging activity of meat substitute by heating. The meat substitute showed higher DPPH radical scavenging activity than those of other foods rich in protein such as beef, pork, chicken, and soybean curd. The DPPH radical scavenging activity of meat substitute was dependent upon concentration, heating temperature and heating time of meat substitute. The DPPH radical scavenging activity of meat substitute was enhanced with increasing heating temperature and time. The increase of DPPH radical scavenging activity was only applied to meat substitute without showing any activation in other foods rich in protein such as beef, pork, chicken, and soybean curd.

• 동아시아식생활학회지
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• 제19권3호
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• pp.375-383
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• 2009

This study was conducted to measure the total polyphenol contents and DPPH radical scavenging activities of different potato plants parts, varieties, and grades, and by distribution and different cooking conditions. The results were as follows. For the plant parts, total phenolic content and DPPH radical scavenging activity were highest in the flowers followed by leaves and stems, respectively. Among 5 potato varieties, 'Jasim' had the highest DPPH radical scavenging activity and the activity of its pulp was lower than that of its cortex(peel). Regardless of potato grade, the cortexes(peel) of samples had two-fold higher DPPH radical scavenging activity than pulp, and the Grade SS potato had the highest phenolic content. It was also found that the bud ends and stem ends had comparably larger amounts of phenolic compounds in horizontally cut potatoes. Finally, the descending order for DPPH radical scavenging activity, according to different cooking conditions, was as follows: gas oven range-baking, frying, microwave-heating, sauteing, boiling in 1% saline solution, steaming, and boiling in 3% saline solution.

• 한국해양바이오학회지
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• 제2권3호
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• pp.187-191
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• 2007

The radical scavenging activity of methanol extracts of seaweeds and their active compounds, alginic acid, fucoidan and phloroglucinol, were investigated under in vitro. Among methanol extracts of seaweeds (sea mustard, sea tangle, seaweed papulosa, fusiforme, sea lettuce, purple laver and chlorella), seaweed papulosa and sea tangle showed strong scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical (${\cdot}OH$). In addition, under in vitro, the scavenging activities on DPPH radical of alginic acid and fucoidan, which are active compounds of brown algae, and phloroglucinol, the active compound from Ecklonia species, were evaluated and compared. Fucoidan and phloroglucinol showed strong DPPH scavenging effect, in particular, phloroglucinol had strongest activity among the active compounds. On the other hand, alginic acid did not exert DPPH scavenging activity. From the present study, we could confirm the antioxidative activity of seaweeds and its active compounds.

• Journal of Nutrition and Health
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• 제38권5호
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• pp.386-394
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• 2005

Effects of root, stem and leaf extract of sancho (Zanthoxylum schinifolium) on the inhibition of lipid peroxidation in the hepatic microsome of rat, DPPH radical scavenging activity and activated partial thromboplastin times (APTT) were examined in vitro. The highest inhibition of hepatic microsomal lipid peroxidation was observed by ethyl acetate fraction than that of methylene chloride fraction of the root and stem extracts. The high inhibition of lipid peroxidation was determined in the leaf, the root and the stem in order. The DPPH radical scavenging activity of ethyl acetate fraction was higher than that of n-butanol fraction and it was similar to the root and the steam extract. It was similar to the inhibition of hepatic microsomal lipid peroxidation. The DPPH radical scavenging activity was the highest in 2.500mg/mL of ethyl acetate fraction and it was 4.4 fold higher than that of $\alpha-tocopherol$, as an antioxidant standard. The DPPH radical scavenging activity was dependent on the extract concentration in the range of 0.125-5.000 mg/mL. The throm-boplastin times were higher than that of n-butanol fraction and it was similar to the root and the steam extracts. The leaf extract showed the highest antithrombogenic effect followed by the stem and then the root extract. The activated partial thromboplastin times were ependent on the extract concentration in the range of 0.100-2.000 mg/mL. Consequently, the effects of antioxidative, DPPH radical scavenging activity and antithrombogenic of Z. schinifolium was observed due to the inhibition of lipid peroxidation and the DPPH radical scavenging activity by methylene chloride, n-butanol and ethyl acetate fraction of the leaf extract. (Korean J Nutrition 38(5): 386 - 394, 2005)

• 한국식품저장유통학회지
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• 제9권2호
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• pp.253-259
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• 2002

민들레 잎과 뿌리로부터 물추출물을 제조하여 항산화 활성 및 라디칼 소거활성을 분석하기 위하여 linoleic acid에 대한 과산화물 생성저해율, DPPH radical에 대한 소거활성, chemiluminescence를 이용한 hydroxyl radical에 대한 소거활성, EPR을 이용한 superoxide anion radical에 대한 소거활성및 hydrogen peroxide에 대한 소거활성을 측정하였다. 그 결과, 민들레 잎의 물추출물이 뿌리의 물추출물 보다 지방산에 대한 과산화물 생성 저해율이 높았고, DPPH radical, hydroxyl radical, superoxide anion radical 및 hydrogen peroxide에 대한 소거활성 역시 매우 높은 것으로 나타났다.

• 한국자원식물학회지
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• 제26권4호
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• pp.426-432
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• 2013

본 연구에서는 미성숙 목화다래 추출물의 항산화능을 알아보기 위해 다래를 크기별로 구분하여 총 폴리페놀 및 플라보노이드 함량과 DPPH radical의 소거능, 아질산염 소거능, ABTS radical 소거능 및 SOD 유사활성을 측정하였다. 추출물의 페놀성 화합물과 플라보노이드 함량은 목화다래의 크기가 작을수록 높게 나타났으며, DPPH radical 소거능 및 ABTS radical의 소거능 또한 작은 크기에서 상대적으로 높은 활성을 보였다. 이는 다른 선행연구들에서와 같이 페놀함량이 높은 실험군에서 DPPH radical 소거능과 ABTS radical 소거능이 높게 나타나 유의성을 확인하였다. 아질산염 소거능은 인체 위 내부환경과 같은 pH 1.2에서는 높은 활성을 보이다가 pH 4.2에서는 점차로 활성이 떨어지는 결과를 보였으며, 중성에 가까운 pH 6.0에서는 아질산염 소거에 영향을 미치지 못하는 것으로 확인되었다. 또한 SOD 유사활성은 대조군인 ascorbic acid에 비하면 낮은 활성이었지만, 기 보고된 다른 천연물들의 효소활성과 비교하였을 때 더 높거나 비슷한 결과를 나타냈다. 이와 같이 본 실험을 통해 미성숙 목화다래의 뛰어난 항산화 활성을 확인할 수 있었으며, 이는 향후 화장품이나 기능성 식품 등에 있어서 새로운 소재개발의 가능성을 시사해주는 것으로서, 그동안 주로 천연 솜의 생산을 위해 재배되어왔던 목화의 제한적 활용성을 더욱 다양하게 해줄 것으로 기대된다.

• KSBB Journal
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• 제32권2호
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• pp.140-145
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• 2017

The objective of this study was to compare antioxidant effects of different extracts of Salicornia bigelovii seed. DPPH radical scavenging activity, chelating activity of ferrous, superoxide anion radical-scavenging activity, hydroxyl radical scavenging activity, and contents of total polyphenol and flavonoid were measured for different extracts. Ethanol extract (10 mg/mL) was found to have the maximum DPPH radical scavenging and superoxide anion radical scavenging activities (65.26 and 62.36%, respectively). However, hot water extract (10 mg/mL) showed the highest hydroxyl radical scavenging and chelating activities (51.50 and 53.24%, respectively). Total phenolics and flavonoid contents in the ethanol extract were 522.8 and $480.35{\mu}g/mg$, respectively. They were 401.51 and $352.60{\mu}g/mg$, respectively, in the hot water extract. These results indicate that ethanol and hot water extracts of S. bigelovii seed have good potential to be used as a new source of antioxidants for functional foods, cosmetics, and pharmaceuticals.

• Fisheries and Aquatic Sciences
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• 제25권6호
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• pp.335-349
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• 2022

To optimize the hydrolysis conditions in the production of antioxidant hydrolysates from tuna cooking juice concentrate (TC) to maximize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, TC containing 48.91% protein was hydrolyzed with Alcalase 2.4 L, and response surface methodology (RSM) was applied. The optimum hydrolysis conditions included a 2.2% (w/v) Alcalase concentration and 281 min hydrolysis time, resulting in the highest DPPH radical scavenging activity of 66.49% (0.98 µmol Trolox/mg protein). The analysis of variance for RSM showed that hydrolysis time was an important factor that significantly affected the process (p < 0.05). The effects of different drying methods (freeze drying, hot air drying, and vacuum drying) on the DPPH radical scavenging activity and amino acid (AA) profiles of TC hydrolysate (TCH) were evaluated. Vacuum-dried TCH (VD) exhibited an increase in DPPH radical scavenging activity of 81.28% (1.20 µmol Trolox/mg protein). The VD samples were further fractionated by ultrafiltration. The AA profiles and antioxidant activities in terms of the DPPH radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power, and ferrous ion chelating activity were investigated. Glutamic acid, glycine, arginine, and cysteine were the major AAs found in the TCH fractions. The highest DPPH radical scavenging activity was found in the VD-1 fraction (< 5 kDa). The VD-3 fraction (> 10 kDa) exhibited the highest ABTS radical scavenging activity and ferric reducing antioxidant power. The ferrous ion chelating activity was the highest in VD-1 and VD-2 (5 to 10 kDa). In conclusion, this study provided the optimal conditions to obtain high antioxidant activities through TCH production, and these conditions could provide a basis for the future application of TCH as a functional food ingredient.

• 한국자원식물학회지
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• 제26권3호
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Food Science and Biotechnology
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• 제15권1호
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• pp.39-43
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• 2006

Levels of quercetin in different parts of onion were investigated using high performance liquid chromatography (HPLC) and liquid chromatography mass spectrometry (LC/MS) suitable for use with functional food material. Two main peaks were observed on HPLC chromatograms from the extracts of the skin, and the outer, middle, and core parts of onion. Using LC/MS, peak 1 was tentatively identified as quercetin monoglucoside at m/z 466.4, and peak 2 as quercetin with [M]+ at m/z 303.3. The levels of quercetin in the skin, and the outer, middle and core parts of the plant were 16.83,2.67,0.95, and 0.35 mg/g, respectively. In the study of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, skin, the nonedible part, contained the highest amount of quercetin, compared to the other edible parts, and showed the highest DPPH radical scavenging activity. Levels of quercetin and DPPH radical scavenging activity increased from core to skin. All parts of onion exhibited the strongest antibacterial activity only against Staphylococcus aureus and Vibro parahaemolyticus. Antibacterial activities of onion exhibited that S. aureus was more sensitive than V. parahaemolyticus. Among the four onion extracts, the middle part showed the strongest inhibitory activity against S. aureus but all onion extracts showed similar antibacterial activities against V. parahaemolyticus.