Browsing by Subject "Scavenging activities"

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    Phenolic content and antioxidant activity of different extracts from ocimum basilicum, apium graveolens and lepidium sativum seeds
    (2011) Aydemir T.; Becerik S.
    The antioxidative properties and total phenolic contents of methanol, ethanol and water extracts from Ocimum basilicum, Apium graveolens and Lepidium sativum seeds were investigated and the results were compared with standards. The methanol extracts of the seeds had significantly higher (P<0.05) superoxide radical scavenging activity with the concentration for 50% inhibition (IC50) value of 98.73μg/mL for O. basilicum, 121.57μg/mL for A. graveolens and 166.16μg/mL for L. sativum. The results indicated that all the seed extracts showed excellent H2O2 scavenging activities. IC50 values for H2O2 scavenging activity by methanol extract of O. basilicum, A. graveolens, L. sativum and butylated hydroxyanisole were found to be as 49.9, 52.3, 65.2 and 49.6μg/mL, respectively. O. basilicum methanol extract had significantly (P<0.05) higher 1,1-diphenyl-2-picryl-hydrazyl scavenging effect than the other two seeds. The methanol extracts of three seeds were better in Fe+2 chelating activity, reducing power and higher in the content of total phenol as compared with ethanol and water extracts. +PRACTICAL APPLICATIONS: Recent epidemiological studies have strongly suggested that consumption of certain plant materials such as seeds, leaves, fruits and roots may reduce the risk of chronic diseases related to oxidative stress on account of their antioxidant activity and promote general health benefits. In this study, all seeds extracts exhibited good antioxidant activity (78.3-96.9%) at concentration 500μg/mL. Total phenolic content in the seed extracts ranged from 51 to 92mg GAE/100g extract. In addition, there was a statistically significant correlation between the amount of phenolic compounds and antioxidant activity (R2=0.9058, P<0.05) in all the seed extracts. Therefore, O. basilicum, A. greveolens and L. sativum seed extracts have the potential to be developed into dietary supplements and nutraceuticals. © 2010 Wiley Periodicals, Inc.
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    Optimisation of microwave effect on bioactives contents and colour attributes of aqueous green tea extracts by central composite design
    (Springer, 2020) Taşkın B.; Aksoylu Özbek Z.
    The aim of the present study was to investigate the effects of microwave-assisted extraction parameters on total phenolic content (TPC), total flavonoid content (TFC), condensed tannins content (CTC), DPPH-scavenging activity, and colour attributes of aqueous green tea extracts and to optimise the microwaving conditions using response surface methodology. Microwave power (120–360–600 W) and irradiation time (1–3–5 min) were selected as independent variables. Statistical analysis revealed that all responses were significantly affected by extraction parameters. The optimum microwave-assisted extraction conditions were 350.65 W microwave power and 5 min irradiation time to maximise TPC, TFC, CTC, DPPH-scavenging activity, and L* values and to minimise a* and b* values of aqueous green tea extracts. The predicted TPC was 116.58 mg gallic acid equivalents/g (GAE/g), TFC was 49.33 mg catechin equivalents/g (CE/g), CTC was 9.89 mg catechin equivalents/g (CE/g), DPPH-scavenging activity (IC50) was 294.46 µg/mL, L* value was 12.31, a* value was 2.61 and b* value was 7.02 under optimum microwave-assisted extraction conditions. This study revealed that microwave extraction conditions should be controlled to obtain aqueous green tea extracts with both high bioactivity and acceptable colour quality. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.