scholarly journals Antioxidant activity of wines and related matters studied by EPR spectroscopy

2009 ◽  
Vol 26 (Special Issue) ◽  
pp. S49-S54 ◽  
Author(s):  
P. Stopka ◽  
J. Křížová ◽  
N. Vrchotová ◽  
P. Bábíková ◽  
J. Tříska ◽  
...  

Antioxidant activity and free radicals were studied in various parts of Vitis vinifera plant in vivo and in wines using EPR spectroscopy. Antioxidative properties of polyphenolic substances play an important role for the evaluation of quality of natural products. Determination of antioxidant activity of experimental samples by EPR method was based on measuring the changes of EPR spectrum of stable nitroxide radicals as a result of their interaction with antioxidants. In the leaves of <i>Vitis vinifera</i> vine varieties for the production of red wines there was observed a higher decrease in free Tempol radicals as compared to the leaves of varieties used for the production of white wines. For all monitored wines there was established a clear decrease in free Tempol radicals to the average value of 75.5 ± 15.6% as compared to the original EPR spectrum. A higher antioxidant activity was observed in yeast sediments from the production of red wines than in those from white ones.

2019 ◽  
Vol 17 (4) ◽  
pp. 371-374
Author(s):  
M. Mihaylov

The direction related with production of vine planting material originated from the 19th century, after the advent of Phylloxera vastatrix F. in which a large part of the vineyards in Bulgaria and the main wine-growing countries were destroyed. Only solution was proposed for grafting vine varieties from Vitis vinifera L. on resistant rootstocks. A number of biological characteristics of the vine influence both the nursery for scions and the rootstock nursery. One of them, which is main is the affinity of different rootstocks on the different vine varieties. In the southern Bulgaria, where the Mavrud variety is characteristic, high losses are observed due to the low yield of first-class vines. In Bulgaria, the Mavrud variety is highly valued due to its biological qualities, resulting in extracts and dense red wines that have glorified our country.


2019 ◽  
Vol 8 (4) ◽  
pp. 48-52
Author(s):  
O. V. Trineeva

Introduction. Recently, much attention has been paid to the primary assessment of the pharmacological effect of various drugs using in vivo and in vitro tests. It is known that such a medicinal plant as sea buckthorn, in its phytochemical composition is rich in natural antioxidants: carotenoids, tocopherols, flavonoids, ascorbic acid, etc. In some publications there is information about the antioxidant activity of sea buckthorn and fatty oil based on them. However, information on the comparative characteristics of the use of various methods for determining the antioxidant activity of this type of medicinal plant material and the results obtained are not found in the scientific literature.Aim. The aim of this work was a comparative determination of the antioxidant activity of medicinal plant material of buckthorn fruits of various species of buckthorn.Materials and methods. The total antioxidant activity of water and water-alcohol extracts from the fruits of sea buckthorn fruits was determined using various techniques recommended in the literature. The antioxidant activity of the extracts was determined by permanganometric titration, in vitro inhibition of adrenaline autooxidation, and also in a biological model, Parametium caudatum cell culture.Results and discussion. The effect of the extractant polarity on the value of antioxidant activity was studied. It was found that the highest content of antioxidants in the extraction is observed when using 96 % ethanol as an extractant.Conclusion. Using three methods, the prospects of using sea buckthorn fruits and preparations based on them as a source of antioxidants are shown. 


Author(s):  
Oleg Odalović ◽  
Danilo Joksimović ◽  
Dušan Petković ◽  
Marko Stanković ◽  
Sanja Grekulović

Within this paper, we evaluated the quality of three Global Geopotential Models entitled: EGM96,EGM2008, and GOCO05c. The models were evaluated by using 1001 terrestrial discrete values ofheight anomalies determined by Global Navigation Satellite Systems and normal heights, which weconsidered to be true values within this research. In addition to the quality evaluation, we tailoredthe models by using more than 80000 free air anomalies. The results obtained from the evaluationand tailoring indicate that by using the GOCO05c it is possible to determine a set of anomaly heightsacross Serbia, which are in agreement with terrestrial values with an average value of -7 cm, thestandard deviation of ±9 cm and with the range of 44 cm.


2020 ◽  
Vol 1 (1) ◽  
pp. 133-140
Author(s):  
Ionica Dina ◽  
Aurora Ranca ◽  
Anamaria Tănase ◽  
Sergiu-Ayar Ene

The climate changes in Murfatlar vineyard in recent years consist inthe increase ofmonthly average temperatures, recorded in both cold and warm seasons, accompanied by an irregular distribution of rainfall during the year, which significantly influences the growth of grapevine, the quality and production of grapes.Six representative cultivars were studied, three for white wines: Chardonnay, Columna and Muscat Ottonel and three for red wines: Fetească Neagră, Mamaia and Cabernet Sauvignon. In the last two years (2019-2020) warm winters and very dry summers have led to the onset of budburst, almost simultaneously for all the studied cultivars, followed by a very weak growth and development of shoots (2020) and an acceleration development of phenophases, mainly berween veraison and ripening. Water stress during the vegetative period, a hygroscopicity below 60% between July and August and low vegetative apparatus influenced the growth ofthe berries, resulting small grapes, and a very low must yield in 2020.Concerning the quality of grape production, the studied cultivars achieved more sugar concentrations in berries up to 35.8 g/L (in 2019) and 36.0 g/L (in 2020), higher than the values obtained in normal years. In the conditions of a pronounced dry climate manifested in the two years of study, the productions were below the normal level, especialy in 2020, achieving much diminished productions for all cultivars, except the Mamaia cultivar. The Mamaia cultivar had a positive reaction, registering an increase of production, that exceeded the multiannual value by 20% in 2020 andby 10% in 2019, the concentration of sugars in the must being above the average value obtained in normal years, exceeding by 3% and 9%, respectively, the multiannual average. Statistical calculations were done using SPSS Statistics 17.0, using mainly the Duncan test for a degree of significance of 5%.


2004 ◽  
Vol 4 (4) ◽  
pp. 143-154 ◽  
Author(s):  
R. Appleyard ◽  
K. Ball ◽  
F. E. Hughes ◽  
W. Kilby ◽  
R. Nicholls ◽  
...  

Purpose: Having previously reviewed the implementation of systematic in vivo dosimetry at the Norfolk and Norwich Hospital this paper examines the results of entrance dose measurements for specific sites/techniques and determines whether different action/alert protocols are required for these different categories.Methods and materials: Entrance dose measurements using p-type diodes were analysed for the following treatment categories: Breast, head and neck in beam direction shell, abdomino-pelvic and intrathoracic. A 4% tolerance was applied.Results: Mean deviations from expected dose and proportion of measurements exceeding tolerance were: Breast: +1.15%±3.04% (1SD), 238/1073≥4%; Head and neck: +0.35%±2.20% (1SD), 21/326≥4%; Abdomino-pelvic: +0.52%±2.75% (1SD), 93/712≥4%; Intrathoracic: −0.01%±2.75% (1SD), 22/119≥4%. Significant improvements in results for breast patients were noted following the introduction of a commercial breast board. The results for abdomino-pelvic patients confirmed a substantial variation in diode response under short FSD, wedged fields at 16MV (that had not been corrected for). The statistical uncertainty in dose measurement for each treatment category was calculated in order to assist determination of appropriate tolerance levels.Conclusions: A blanket tolerance of 4% was generally too low given the extent of measurement uncertainty. The relatively high number of readings outside tolerance where identification of errors was difficult/impossible resulted in inconsistent application of the action protocol. Some widening of tolerances is likely to improve quality of procedure and treatment. Appropriate action levels are recommended for each treatment category.


Phytomedicine ◽  
2009 ◽  
Vol 16 (8) ◽  
pp. 761-767 ◽  
Author(s):  
C.G. Silva ◽  
R.J. Raulino ◽  
D.M. Cerqueira ◽  
S.C. Mannarino ◽  
M.D. Pereira ◽  
...  

2017 ◽  
Vol 62 (5) ◽  
pp. 233-240
Author(s):  
E. L. Postnova ◽  
N. V. Shalunova ◽  
K. A. Sarkisyan ◽  
A. A. Movsesyants

The immunologic activity (specific activity) is one of the main indicators of quality of vaccines for prophylaxis of hepatitis B, along with their safety. Retrospective analysis of the use of laboratory methods for assessment of specific (immunogenic) activity of modern vaccines against hepatitis B using indicators was carried out: in vitro method based on evaluation of HBsAg content and in vivo method based on evaluation of immunogenic activity in mice. Both methods are standardized and described in normative documents on the vaccines against hepatitis B of domestic production registered in the Russian Federation. Indicators of specific (immunogenic) activity of vaccines against hepatitis B were used to investigate more than 170 vaccine series using the ELISA method in the period from 2013 to 2015. The obtained control results confirmed the expediency and efficiency of enzyme immunoassay for determination of HBsAg content, as well as permissibility of use of ready sets of the Murex HBsAg Version 3 test systems for testing vaccines against hepatitis B by the ELISA method. Analysis of the results of laboratory control of series of vaccines against hepatitis B using a biological method for immunogenicity evaluation based on ED50 analysis confirms persistently high immunogenic activity of the Russian commercial vaccines intended for prophylaxis of hepatitis B. The confirmed comparability of methods allows the number of in vivo tests to be further reduced in favor of the enzyme immunoassay authentically characterizing the produced drug.


Foods ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 474 ◽  
Author(s):  
Domenico Cautela ◽  
Filomena Monica Vella ◽  
Bruna Laratta

Experimental and epidemiological studies show a positive relation between consumption of citrus juices and reduction of risk for some chronic disorders, such as diabetes and cardiovascular diseases. In particular, the bergamot juice is characterized by noticeable amounts of phytochemicals such as flavanone glycosides, limonoids, and quaternary ammonium compounds, all health-beneficial biomolecules. In vitro and in vivo studies have shown anti-inflammatory, cholesterol-lowering, and anti-diabetic activities attributed to these compounds depending on their chemical structure. However, nutritional content of bergamot juice may vary as consequence of different processing techniques, thus needing to address this claim. For this reason, the objective of this research was to evaluate the effects of different processing systems on the proximate constituents, the composition, and the antioxidant activity of the correspondent juices. Overall, the results indicate that the process employed may influence the chemical composition and the functional properties of the ended juice. Screw press method produced a juice with greater content of flavanone glycosides (ranged from 37 to 402 mg/L) and limonoid aglycones (ranged from 65 to 67 mg/L) than the other processes (p < 0.001). However, the process used for extraction of bergamot juice did not affect significantly the N,N-dimethyl-L-proline content (p < 0.5). Moreover, the screw press juice showed the highest antioxidant activity with EC50 value of 9.35 µg/mL, thus suggesting that this method maintains for health the nutritional quality of a fresh-pressed juice.


2019 ◽  
Vol 7 (9) ◽  
pp. 2932-2938 ◽  
Author(s):  
James D. House ◽  
Kristen Hill ◽  
Jason Neufeld ◽  
Adam Franczyk ◽  
Matthew G. Nosworthy

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