scholarly journals Antioxidant Activity of Selected Apple Cultivars Studied by Electron Paramagnetic Resonance

2015 ◽  
Vol 57 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Krunoslav Mirosavljević ◽  
Branka Bilić ◽  
Teuta Benković-Lacić
Keyword(s):  
Antioxidant Activity ◽  
Electron Paramagnetic Resonance ◽  
Exponential Decay ◽  
Total Antioxidant Activity ◽  
Paramagnetic Resonance ◽  
First Order ◽  
Golden Delicious ◽  
Total Antioxidant ◽  
Apple Cultivars ◽  
Electron Paramagnetic

Abstract The total antioxidant activity of three apple cultivars conventionally farmed (Jonagold, Golden Delicious and Idared) and two cultivars organically farmed (Jonagold and Golden Delicious) were investigated by electron paramagnetic resonance (EPR) spectroscopy. The spin label used for experiments was TEMPO radical (2,2,6,6-tetramethylpiperidine-1-oxyl) with a well-defined EPR spectrum consisting of three equidistant peaks. The results obtained indicated difference in the total antioxidant activity of apples grown in two different ways, conventional and organic, as well as between different cultivars grown in the same way. The Golden Delicious cultivar is richer in antioxidants than the Jonagold and Idared, regardless of the method of farming. The difference between them is higher in conventionally grown apples than in organically farmed apples. Experimental data was fitted with non-linear curve fit for exponential decay of the first order based on the Levenberg-Marquardt method. The high values of the R2 parameters for all data indicated correctness in the proposition of exponential decay of the first order as a model describing the dynamic properties of spin labels which diminish in the presence of fresh apple juice.

scholarly journals Physicochemical properties and antioxidant activity of two varieties of apple cultivated in different areas in Morocco

2020 ◽  
Vol 10 (4) ◽  
pp. 371
Author(s):  
Driss Oussaid ◽  
Ismail Mansouri ◽  
Hassan Laaroussi ◽  
Badiaa Lyoussi ◽  
Ilham El Aarabi
Keyword(s):  
Antioxidant Activity ◽  
Physicochemical Properties ◽  
Physicochemical Parameters ◽  
Total Antioxidant Activity ◽  
Flavonoid Content ◽  
Polyphenol Content ◽  
Bioactive Substances ◽  
Golden Delicious ◽  
Total Antioxidant ◽  
Apple Cultivars

<p class="Mabstract">This study aimed to assess the effect of climate on the organoleptic qualities and phytochemical properties of two varieties of apple (<em>Golden delicious</em> (GD) and <em>Red delicious</em> (RD)) collected from different regions in Morocco. These two varieties of apple were examined for their bioactive compounds composition and antioxidant activity (in juice and different extracts). For physicochemical parameters, the highest acidity was observed in <em>Golden delicious</em> collected from station 1, which was the juiciest sample. Bioactive substances content was dependent on variety and station, while the highest polyphenol content was observed in <em>Golden delicious</em> collected from station 2 (135.41±6.66 mg GAE/100 mL of juice) and most top flavonoid content was observed in <em>Red delicious</em> collected from station 1 (7.43±0.13 mg QE/100 mL of juice). Furthermore, <em>Red delicious</em> collected from station 2 was the most effective in chelating the radical DPPH (IC50% = 0.92±0.01 µL of juice), and <em>Red delicious</em> collected from station 1 has the highest total antioxidant activity (2.47±0.02 mg AAE/100 mL of juice). The present work showed that the significant diversity in the different studied parameters of the apple cultivars was closely linked with the characteristics of the station, such as geography and climate.</p>

scholarly journals Determining the Dose of Radiation and Radurisation Effects on the Antioxidant Activity of Fish and the Thermophysical Characteristics of Fish Muscle Tissue

Foods ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 130
Author(s):  
Roza T. Timakova ◽  
Sergey L. Tikhonov ◽  
Nataliya V. Tikhonova ◽  
Sergey V. Shikhalev
Keyword(s):  
Antioxidant Activity ◽  
Electron Paramagnetic Resonance ◽  
Radiation Dose ◽  
Muscle Tissue ◽  
Radiation Treatment ◽  
Fish Muscle ◽  
Radiation Processing ◽  
Thermophysical Characteristics ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The aim of this article is to develop a method for determining the dose of radiation in the processing of chilled fish and its effect on the antioxidant activity and thermophysical characteristics of muscle tissue. Radiation processing of chilled fish was performed using a linear electron accelerator model LEA-10-10S2. The dose of radiation was determined by the method of electron-paramagnetic resonance. After being treated with ionizing radiation, the cooled fish meets the requirements of the technical regulations of TR TU 021/2011 “On food safety” and TR EAEU 040/2016 “On the safety of fish and fish products”. As a result of our research, a correlation was established between the area of the Electron Paramagnetic Resonance (EPR) signal and the absorbed dose of the radiation dose. We proved a decrease in the antioxidant activity of muscle tissue of fish with an increase in radiation dose. It is established that radiation treatment of chilled fish affects the thermophysical properties of muscle tissue.

Generation and Dissociation of Iron-Boron Pairs in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
Masashi Suezawa ◽  
Koji Sumino
Keyword(s):  
Activation Energy ◽  
Electron Paramagnetic Resonance ◽  
Reaction Kinetics ◽  
Order Reaction ◽  
Migration Energy ◽  
Paramagnetic Resonance ◽  
First Order ◽  
Pair Generation ◽  
Electron Paramagnetic ◽  
Fe Impurity

AbstractThe generation and dissociation processes of Fe-B pairs in Si crystal are investigated by means of the measurements of electron paramagnetic resonance of Si crystals of various B concentrations doped with Fe. Fe-B pairs are generated due to annealing of the crystals at temperatures around 300 K obeying to the first order reaction kinetics. The activation energy for pair generation is determined to be about 0.65 eV which is almost equal to the migration energy of Fe impurity in a Si crystal. Fe-B pairs are found to be dissociated at tempeatures higher than 150°C leading to the precipitation of Fe.

Evaluation of total antioxidant and free radical scavenging activities of Callistemon citrinus (Curtis) Skeels extracts by biochemical and electron paramagnetic resonance analyses

RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12382-12390 ◽  
Author(s):  
Sowndarya Sampath ◽  
Balasaraswathi Kalimuthu ◽  
Vidhya Veeramani ◽  
Sridevi Janardhanam ◽  
Mandal Asit Baran ◽  
...  
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Scavenging Activity ◽  
Paramagnetic Resonance ◽  
Total Antioxidant ◽  
Electron Paramagnetic ◽  
Free Radical Scavenging Activities

Free radical scavenging activity of Callistemon citrinus (Curtis) Skeels extracts analysed using biochemical and Electron Paramagnetic Resonance (EPR) studies.

scholarly journals Teas: Direct Test on Quality and Antioxidant Activity using Electron Paramagnetic Resonance Spectroscopy

2002 ◽  
Vol 16 (3-4) ◽  
pp. 371-378 ◽  
Author(s):  
M. A. Morsy
Keyword(s):  
Antioxidant Activity ◽  
Electron Paramagnetic Resonance ◽  
Green Tea ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Oxidative Degradation ◽  
Paramagnetic Species ◽  
Resonance Spectroscopy ◽  
Stable Free Radical ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic

The manufactured teas may conveniently be divided into three classes: Green teas, Oolongs (delicate black teas), and Black Teas. Several indirect methods are employed to measure the antioxidant activity of tea extracts that is basically takes place by monitoring the inhibition of oxidation of a suitable substrate using the extracts of antioxidant materials from the studies systems. This study is concerned with the results of electron paramagnetic resonance (EPR) spectroscopy that is utilized to investigate several categories of green and black teas: Twining Green Tea (TGT) of London, Rabea Green Tea (RGT) of Saudia, Chinese Green Tea (CGT) of China, English Breakfast Tea (EBT) of Ahmed Tea-London, and Rabea Black Tea (RBT) of Saudia. Three EPR signals from all the studied samples are observed. The assignment of these signals will discussed and correlated with the quality of leaves. Mainly, two paramagnetic species are considered to be responsible for the observed EPR signals; manganese(II)–protein system of the leaves and a stable free radical of aromatic origin. The study will provide facts on the dependency of radical signal on the oxidative degradation procedures of the studied samples. The intensity and feature of Mn(II)-EPR-signal is found to be related to the disintegration of tea leaves.

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