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From a screening of six different samples of grape stems from Vitis vinifera Sicilian cultivars, "Nerello Mascalese" as well as "Nero d'Avola" ethanol extracts showed promising radical scavenging activity and phenol content (DPPH....
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From a screening of six different samples of grape stems from Vitis vinifera Sicilian cultivars, "Nerello Mascalese" as well as "Nero d'Avola" ethanol extracts showed promising radical scavenging activity and phenol content (DPPH. and GAE assays). Aliquots of these three extracts were subjected to two different fractionation protocols on polyamide (PF) and Amberlite XAD-16 (XF). The fractions were examined by DPPH. and GAE assays, and subjected to HPLC-DAD analysis for the quantitative determination of the main phenolic compounds. Fractionation of the crude extract NM1E (SC50 = 28.2, GAE = 221.0) through the XF protocol, afforded a polyphenol-enriched fraction (XF1C, GAE = 392.5) with highly enhanced antioxidant activity (SC50 = 7.0), and accounting for only 6.5% in weight of the NM1E extract. Fraction XF1C shows high concentrations of a procyanidin B1 (Pcd) and catechin (Cat). Some considerations on the relationship between antioxidant activity and phenolic HPLC-DAD profiles are also reported
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Fruit flavored curd is prepared by adding pineapple juice with lactic fermented milk. The physicochemical, organoleptic and rheological properties are analyzed to assay the quality of the curd. Physicochemical properties of curd s...
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Fruit flavored curd is prepared by adding pineapple juice with lactic fermented milk. The physicochemical, organoleptic and rheological properties are analyzed to assay the quality of the curd. Physicochemical properties of curd samples including moisture, acidity, pH, ash, total carbohydrate and total polyphenols content are determined for all the samples. In this study, many trials have been done with different proportion of pineapple juice i.e. 5%, 7.5%, 10%, 12.5% and 15%. Initially due to bitterness of the final product, the process is modified by giving heat treatment to raw pineapple juice at 65C for 10 min. Finally the sensory evaluation of the products are carried out and according to the panel of judges, overall acceptability of 12.5% juice fortified product is superior in comparison to others. Therefore, curd fortified with 12.5% pineapple juice is selected for further analysis i.e. moisture content, ash content, pH, acidity, total polyphenols content and total carbohydrates and the results are 69.11%, 1.23%, 5.08,0.81%, 1.67g GAE/lOOg and 12.19g/ 1 OOg respectively. The results of current study demonstrated that the addition of fruits to the curd significantly improved the quality of curd.
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2,2-Diphenyl-1-picrylhydrazyl (DPPH) method is routinely practiced for the assessment of antioxidant activity of compounds and their mixtures. The method is based on the spectrophotometric measurement of DPPH concentration that ch...
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2,2-Diphenyl-1-picrylhydrazyl (DPPH) method is routinely practiced for the assessment of antioxidant activity of compounds and their mixtures. The method is based on the spectrophotometric measurement of DPPH concentration that changes resulting from the DPPH radical reaction with an antioxidant. The amount of remaining DPPH in the examined system is a measure of the antioxidant activity of compounds. Our study aims at exploring the antioxidant properties of Justicia adhatoda leaf extract and comparing the results in terms of effective concentration which scavenges 50 % radical (EC50). The correlation of the activities for both cold and Soxhlet methanolic extracts is reported with DPPH assay. The antioxidant capacity of the methanolic extract derived by two different methods is positively correlated. Correlation between antioxidant capacity and phenolic content of methanolic extract in both the cases indicates the efficiency of the extraction procedure. Positive correlation and p value <0.05 validate the efficiency of the procedures and results.
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Recent upgrades in H-1 power supplies have enabled the operation of the H-1 experiment at higher heating powers than previously attainable. A heating power scan in mixed hydrogen/helium plasmas reveals a change in mode activity wi...
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Recent upgrades in H-1 power supplies have enabled the operation of the H-1 experiment at higher heating powers than previously attainable. A heating power scan in mixed hydrogen/helium plasmas reveals a change in mode activity with increasing heating power. At low power (< 50 kW) modes with beta-induced Alfven eigenmode frequency scaling are observed. At higher power modes consistent with an analysis of nonconventional global Alfven eigenmodes (GAEs) are observed, the subject of this work. We have computed the mode continuum, and identified GAE structures using the ideal MHD solver CKA and the gyrokinetic code EUTERPE. An analytic model for ICRH-heated minority ions is used to estimate the fast ion temperature from the hydrogen species. Linear growth rate scans using a local flux surface stability calculation, LGRO, are performed. These studies demonstrate drive from the radial spatial gradient of circulating particles whose speed is significantly less than the Alfven speed, and are resonant with the mode through harmonics of the Fourier decomposition of the strongly shaped heliac magnetic field. They reveal drive is possible with a small (n(f)/n(0) < 0.2) hot energetic tail of the hydrogen species, for which T-f > 300 eV. Local linear growth rate scans are also complemented with global calculations from CKA and EUTERPE. These qualitatively confirm the findings from the LGRO study, and show that the inclusion of finite Larmor radius effects can reduce the growth rate by a factor of up to ten, and increases the marginal stability fast ion temperature by a factor of two. Finally, a study of damping of the global mode with the thermal plasma is conducted, computing continuum damping, and the damping arising from finite Larmor radius and parallel electric fields ( via resistivity). We find that continuum damping is of order 0.1% for the configuration studied. A similar calculation in the cylindrical plasma model produces a frequency 35% higher and a damping 30% of the
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The paper presents the first reported observation of high frequency Alfven eigenmode excitation on the ASDEX Upgrade tokamak. The mode is driven in a novel way using radio frequency (RF) wave acceleration of either beam-injected d...
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The paper presents the first reported observation of high frequency Alfven eigenmode excitation on the ASDEX Upgrade tokamak. The mode is driven in a novel way using radio frequency (RF) wave acceleration of either beam-injected deuterium ions or thermal He-3 minority ions in a three-ion heating scenario. In the case of beam ion acceleration, the instability only appears during deuteron acceleration at the third beam ion cyclotron harmonic (wave frequency ω = 3Ω_D where Ω_D is the deuterium cyclotron frequency), as the mode is not detected during the more commonly used second harmonic/minority heating scenario or in the absence of beam-injected ions. The mode frequency is around 0.6-0.7Ω_D, where Ω_D is evaluated in the low-field side plasma edge, and tracks the magnetic field B and the edge plasma electron density n_e via the Alfvenic relation ω ~ B n_e~(-1/2). The mode does not appear as a single frequency wave but as a bundle of closely spaced (in frequency) sub-modes. When the parallel beam ion velocity component is increased, the sub-mode frequency spacing is observed to decrease, possibly due to a change in the eigenmode structure. Under certain conditions, typically in discharges with a relatively low plasma current, I_P < 0.7 MA, the mode appears to be driven directly by sub-Alfvenic deuterium beam ions. Absolute measurements of the mode amplitude show that at least 1% of the beam-injected power is transferred non-collisionally to the instability. While this is too low for practical alpha-channeling applications, discharges are planned with the aim of increasing the level of power transferred non-collisionally between fast ions and the instability.
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Free radicals produced during cellular metabolism are responsible for various diseases. Thus, looking for natural antioxidants from medicinal plants has now become an important research. Aegle marmelos, commonly known as bael, is ...
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Free radicals produced during cellular metabolism are responsible for various diseases. Thus, looking for natural antioxidants from medicinal plants has now become an important research. Aegle marmelos, commonly known as bael, is a tropical tree valued for its medicinal properties and has been used to cure many diseases. In the present study, antioxidant activity and phenolic profile of the bael leaf, bark and fruit were investigated. The methanolic extracts of bael leaf, bark and fruit were assayed for their antioxidant activities using DPPH (2,2-diphenyl, 2-picrylhydrazyl) radical scavenging activity, reducing power and chelating metal ion power. The highest DPPH radical scavenging activity was observed in leaf methanolic extract (50% inhibition (IC50) value = 249.3 +/- 9.4 mu g mL(-1)) and least in fruit methanolic extract (IC50 = 1032.2 +/- 7.03 mu g mL(-1)). Highest chelating power was observed in leaf methanolic extract (IC50 = 165.7 +/- 2.3 mu g mL(-1)) and least in fruit methanolic extract(IC50 = 977 +/- 5.7 mu g mL(-1)) whereas the IC50 of reducing power ranged from 0.4 to 05 mu g mL(-1). Total phenolic content was highest in leaf methanolic extract (16.5 +/- 0.3 mg gallic acid equivalents (GAE) g(-1) dry weight) and lowest in fruit methanolic extract (10.6 +/- 0.3 mg GAE g(-1)). Reversed-phase HPLC analysis of the leaf, bark and fruit methanolic extracts, revealed the presence of different phenolic acids, viz. gallic acid, p-coumaric acid, vanillic acid, p-hydroxy benzoic acid, syringic acid, ferulic acid and chlorogenic acid.
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