Search results for " Capacity"
showing 10 items of 902 documents
The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay
2019
The DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay is an easy and efficient method commonly used to determine the antioxidant capacity of many food matrices and beverages. In contrast with red wines, white wines are poorer in antioxidant polyphenolics, and the more hydrophilic sulfur-containing compounds in them may contribute significantly to their antioxidant capacity. The modification of the classical DPPH method, with a methanol-buffer and the measure of EC20 (quantity of sample needed to decrease the initial DPPH concentration by 20%) has shown that sulfur-containing compounds such as cysteine (0.037 ±
Lidocaine inhibits potassium efflux and hemolysis in erythrocytes during oxidative stress in vitro.
2000
Lidocaine is a widely used local anesthetic agent. The aim of this work was to study the action of lidocaine on human red blood cells exposed to an oxidative stress in vitro. Blood was obtained from healthy volunteers. After separation from plasma, the erythrocytes were suspended in phosphate buffer. Oxidative stress was induced by incubation with a free radical generator, the 2,2' azobis (2-amidinopropane) hydrochloride (AAPH). Erythrocytes were incubated with or without lidocaine at two concentrations (36.93 and 73.85 microM) and with or without AAPH (20 mM). Electron paramagnetic resonance (EPR) spectroscopy was performed to identify the free radical species generated by AAPH using the s…
Polyphenol Characterization, Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark
2019
In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel.) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP-LC-DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose-dependent antioxidant and free-radical scavenging activity, expressed as half-maximal inhibitory concentration (IC50 ): Oxygen radical absorbance capacity (ORAC, IC50 1.78 μg mL-1 )>Trolox equivalent antioxidant capacity (TEAC, IC50 3.47 μg mL-1 )>2,2-Diphenyl-1-picrylhydrazyl (DPPH, IC50 5.83 μg mL-1 )>β-carotene bleaching (IC50 11.58 μg mL-1 )…
Quality parameters, bioactive compounds and their correlation with antioxidant capacity of commercial fruit-based baby foods
2013
Comprehensive research is required to achieve the optimization of the antioxidant protection through baby foods, in particular, the commercially available fruit-based baby foods. This study investigated the physicochemical properties, ascorbic acid (AA), total carotenoids (TC), total phenolic content (TPC), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) of 23 different commercially available fruit-based baby foods. The main contribution to the total antioxidant capacity (trolox equivalent antioxidant capacity and oxygen radical absorbance capacity) was provided by ascorbic acid, followed by phenolic compounds, in accordance with a mathematical e…
Antioxidant activity of 5-FU and new fluorinated uracil derivates
2017
The intake of antioxidants has increased in the last years in order to treat some pathologies associated with oxidative stress such as cancer, diabetes mellitus, atherosclerosis, myocardial infarction, acute pancreatitis, Parkinson's and Alzheimer's disease among others. In colorectal cancer, a widely antineoplastic drug used is the fluorinated uracil molecule 5-Fluorouracile (5-FU). The aim of this study is to assess the antioxidant capacity observed by the inhibition of lipid peroxidation by 5-FU and other fluorinated uracil derivates: 6-[Difluoro(phenyl)methyl]-3-(2,4,6-trifluorophenyl)pyrimidine-2,4(1H,3H)-dione (S-81), 3-[2-Chloroethyl]-6-[difluoro(phenyl)methyl]pyrimidine-2,4(1H,3H)-d…
Salmon (Salmo salar) side streams as a bioresource to obtain potential antioxidant peptides after applying pressurized liquid extraction (PLE)
2021
The pressurized liquid extraction (PLE) technique was used to obtain protein extracts with antioxidant capacity from salmon muscle remains, heads, viscera, skin, and tailfins. A protein recovery percentage ≈28% was obtained for all samples except for viscera, which was ≈92%. These values represented an increase of 1.5–4.8-fold compared to stirring extraction (control). Different SDS-PAGE profiles in control and PLE extracts revealed that extraction conditions affected the protein molecular weight distribution of the obtained extracts. Both TEAC (Trolox equivalent antioxidant capacity) and ORAC (oxygen radical antioxidant capacity) assays showed an outstanding antioxidant activity for viscer…
Accelerated Solvent Extraction and Pulsed Electric Fields for Valorization of Rainbow Trout (Oncorhynchus mykiss) and Sole (Dover sole) By-Products: …
2021
Fishery by-products are rich in biologically active substances and the use of green and efficient extraction methods to recover these high-added-value compounds is of particular importance. In this study, head, skin and viscera of rainbow trout and sole were used as the target matrices and accelerated solvent extraction (ASE) (45–55 °C, 15 min, pH 5.2–6.8, 103.4 bars) and pulsed electric fields (PEF) (1–3 kV/cm, 123–300 kJ/kg, 15–24 h) were applied as extraction technologies. The results showed that ASE and PEF significantly increased the protein extract efficiency of the fish by-products (p < 0.05) by up to 80%. SDS-PAGE results showed that ASE and PEF treatments changed the molecular size…
Changes in Levels of a-Tocopherol and Ascorbate in Spruce Needles at Three Low Mountain Sites Exposed to Mg2+-Deficiency and Ozone
1994
The main objective of this study was the com parison of changes in levels of α-tocopherol and ascorbate in needles of spruce trees with various degrees of damage at three low mountain sites. The ascorbate content in needles of spruce trees with various degrees of dam age differs in the course of seasons as well as in the absolute level. The antioxidant status was affected mainly during summer. The content of ascorbate in needles of dam aged trees was significantly increased compared to that of undamaged trees. Despite seasonal and daily fluctuations, the level of ascorbate seems to be a good indicator for the degree of dam age in the case of symptoms described as montane yellowing. Together…
Plant Sterols and Antioxidant Parameters in Enriched Beverages: Storage Stability
2012
Plant sterols (PS) stability, antioxidant parameters, and color were studied during 6 months of storage at 4, 24, and 37 °C in three PS-enriched functional beverages. Beverages were skimmed milk with fruit juice and PS (MFJPS), fruit juice and PS (FJPS), and skimmed milk with PS (MPS). No loss in total PS content occurred during storage observing the same values at any given storage time point. Total carotenoids decreased 36% with storage at two months and then remained stable. Total polyphenols showed fluctuations throughout the storage, remaining stable at 6 months and reaching initial values. The antioxidant capacity (TEAC method) increased 18% at 6 months, and there was an increase in c…
Serum antioxidant capacity and peroxide level of seven healthy subjects after consumption of different foods
2016
This article reports experimental data related to the research article entitled “Different effectiveness of two pastas supplemented with either lipophilic or hydrophilic/phenolic antioxidants in affecting serum as evaluated by the novel Antioxidant/Oxidant Balance approach” (M.N. Laus, M. Soccio, M. Alfarano, A. Pasqualone, M.S. Lenucci, G. Di Miceli, D. Pastore, 2016) [1]. Antioxidant status of blood serum of seven healthy subjects was evaluated during four hours after consumption of two functional pastas, supplemented with either bran oleoresin or bran water extract obtained from durum wheat. For comparison, the effect of a non-supplemented reference pasta was also evaluated, as well as t…