scholarly journals Changes of antioxidant activity and active compounds content in selected teas

2020 ◽  
Vol 8 (1) ◽  
pp. 91-97
Author(s):  
Barbara Kolodziej ◽  
Sugier Danuta ◽  
Luchowska Katarzyna

Our study tested 45 tea infusions classified into five groups (white, green, red, black, and other teas) for the content of total polyphenols and flavonoids, as well as antioxidant properties, by the FRAP and DPPH methods. We examined these parameters after prolongation of the brewing time from 10 to 30 min and overnight storage. The results showed that the capacity of the teas to bind free radicals was differentiated and the amount of anti-oxidant compounds depended on their nature. In terms of antioxidant activity and total polyphenol content, the tested tea types were ranked in the following order: white > green > black > red > other teas (yerba mate > rooibos). Our experiment demonstrated a positive correlation between the polyphenol content and antioxidant activity of the analyzed teas. Also, the DPPH antiradical efficiency was comparable to their ability to reduce ferric ions. The extended brewing time had a significant effect on the antioxidant activity of the infusions and the polyphenolic compounds analyzed therein. In contrast, storage of the infusions for 24 h at room temperature changed their antioxidant activity and affected the total polyphenol content.

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 283 ◽  
Author(s):  
Bogumiła Urbańska ◽  
Jolanta Kowalska

The polyphenol content of cocoa beans and the products derived from them, depend on the regions in which they are grown and the processes to which they are subjected, especially temperature. The aim of the study was to compare the total content of polyphenols and antioxidant activity of chocolates obtained from roasted and unroasted cocoa beans. The chocolates produced from each of the six types of unroasted beans and each of the five types of roasted beans were investigated. The seeds came from Ghana, Venezuela, the Dominican Republic, Colombia and Ecuador. The highest total polyphenol content was determined in cocoa beans originating from Colombia and in the chocolates obtained from them. A higher content of total polyphenols was found in unroasted cocoa beans, which indicates the influence this process had on the studied size. The ability to scavenge free DPPH radicals was at a high level in both the beans and the chocolates produced from them, irrespective of the region where the raw material was grown. A positive correlation between the total polyphenol content and the ability to scavenge free radicals was found.


2016 ◽  
Vol 34 (No. 4) ◽  
pp. 318-324 ◽  
Author(s):  
P. Novotná ◽  
J. Tříska ◽  
P. Híc ◽  
J. Balík ◽  
N. Vrchotová ◽  
...  

Red and white musts were enriched with the lignan hydroxymatairesinol, which is the main lignan contained in spruce knots. Chips from the milled spruce knots were then used to enrich grape musts. After enrichment, the musts were stored and samples were taken in 1, 5, 9, and 12 months. The samples were subjected to a variety of analyses and sensory evaluations. Analyses included hydroxymatairesinol and alpha-conidendrin content, antioxidant activity (determined by the FRAP method), content of total polyphenols, sensory evaluation (intensity of woody aroma, intensity of bitterness and astringent taste, and consumer acceptability), and must antimutagenicity. The analysis of variance allowed predicting which factors such as grape type, quantity of added wood chips, sugar addition, method of preservation, and storage time had the most significant influence on the analytical parameters (lignan content, antioxidant activity, and total polyphenol content). In all cases lignan content in the musts was significantly influenced by the addition of spruce wood chips. Total polyphenol content in the musts was significantly affected by the type of musts and by heat treatment (time of thermomaceration). Evaluation of must antimutagenicity showed that all samples, except the sample of white musts after thermomaceration without holding at temperature and without adding chips (10 g/20 kg mash), inhibited mutagenicity.


2013 ◽  
pp. 269-277 ◽  
Author(s):  
Zoran Maksimovic ◽  
Nebojsa Nedic

Antioxidant properties of fifteen multifloral and honeydew types of honey from Serbia were assessed by determination of ferric-reducing antioxidant power (FRAP assay) and 2,2- diphenyl-1-picrylhydrazyl free radical scavenging ability (DPPH assay), with respect to their total polyphenol content and colour intensity. The results of this study showed that total polyphenol content, antioxidant activity and colour intensity varied widely among different samples, even within the same type of honey. All investigated parameters were strongly dependent on geographic origin of samples, further emphasizing the importance of their detailed chemical characterisation. In general, polyphenolic content in investigated samples of honey, expressed as catechin equivalents, ranged from 480.2 to 1861.1 mg/kg. The ferric-reducing antioxidant power of honey tended to be lower in brighter and higher in darker samples, varying between 489.6 and 3089.8 ?mol Fe(II) per 100 g of honey. The correlation between the colour and antioxidant activity never reached statistical significance in the case of honeydew type of honey, which was opposed to a trend observed in the case of multifloral honey.


2014 ◽  
Vol 12 (6) ◽  
pp. 700-710 ◽  
Author(s):  
Joanna Ronowicz ◽  
Bogumiła Kupcewicz ◽  
Elżbieta Budzisz

AbstractIn this study, antioxidant properties of commercial green teas and dietary supplements containing Camellia sinensis extracts were evaluated. Extracts were examined using two antioxidant assays (DPPH· radical method and ABTS·+ cation radical method). A Folin-Ciocalteu assay was used to evaluate the total polyphenol content in the extracts. In order to compare and characterize the investigated Camellia sinensis extracts, chemometric techniques based on fingerprint chromatograms, antioxidant activity and total polyphenol content were applied. Application of chemometric methods allowed for reduction of multidimensionality of the data set and grouped the samples into differentiable clusters. The relationship between the antioxidant activity and total polyphenol content was also assessed. The results indicated that extracts with the higher polyphenolic content exhibited the stronger antiradical activity against both DPPH· radicals and ABTS·+ cation radicals. The multivariate calibration technique (such as a tree regression algorithm) can be a useful tool for rapid determining the antioxidant activity of a herbal product based on its fingerprint chromatogram


2013 ◽  
Vol 31 (No. 6) ◽  
pp. 613-618 ◽  
Author(s):  
D. Bajčan ◽  
J. Tomáš ◽  
G. Uhlířová ◽  
J. Árvay ◽  
P. Trebichalský ◽  
...  

We evaluated changes in the content of total polyphenols and antioxidant activity of frozen spinach, peas, and sweet corn in relation to the storage period. Total polyphenol content and antioxidant activity in analysed samples were determined by colorimetric methods. Both parameters were analysed in frozen samples monthly and the changes were monitored during storage in a freezing box at a temperature of –18°C for 10 months. Freezing had a different influence on the levels of total polyphenol content and antioxidant activity in individual analysed samples. The greatest decrease in antioxidant activity during the entire period of freezing was recorded in spinach (79.4%), while the lowest decrease was observed in peas (26.8%). A relatively significant decrease in antioxidant activity was also found in sweet corn (62.7%). On the contrary, the greatest decrease of total polyphenol content throughout the period of freezing was found in peas (62.0%), and lowest decrease was recorded in sweet corn (only 5.0%). The total polyphenol content in spinach decreased by 43.1% after 10 months of storage.


2013 ◽  
Vol 30 (3) ◽  
pp. 263-269 ◽  
Author(s):  
Renata Kazimierczak ◽  
Ewelina Hallmann ◽  
Anna Rusaczonek ◽  
Ewa Rembiałkowska

AbstractAmong infusions of green teabags and leafy green teas from organic and non-organic production systems we measured and compared the content of phenolic acids, flavonols and total polyphenols by spectrophotometry, the content of tannins by titration and the content of caffeine by high-performance liquid chromatography (HPLC). In addition, the antioxidant activity of the infusions was determined by spectrophotometry. The results obtained have shown that organic teas contained significantly more flavonols and tannins. However, the content of phenolic acids was higher in non-organic teas. The teas from organic and non-organic production did not differ in terms of total polyphenol content and antioxidant activity. There were no differences in leaf teas in relation to the teabags in contents of phenolic acids, tannins and total polyphenols. Organic teas had higher content of catechin C than the non-organic ones, but at the same time non-organic teas had more epigallocatechin 3-gallate (EGCG) in comparison to organic teas. Epigallocatechin (EGC) and epicatechin (EC) were not found to be different between the two groups of tea. Catechin was found to be significantly higher in teabags, while the EGCG was higher in leaf teas. The reason for this may be the oxidation of teabags, which have a greater exposed surface area. There was no appreciable effect of the form of tea on the content of tannins, caffeine, flavonols, phenolic acids, total polyphenols, EGC and EC as well as the antioxidant activity of the tea infusions examined.


2016 ◽  
Vol 34 (No. 5) ◽  
pp. 439-444 ◽  
Author(s):  
Balík Josef ◽  
Híc Pavel ◽  
Kulichová Jana ◽  
Novotná Pavla ◽  
Tříska Jan ◽  
...  

Red and white wines [Grüner Veltliner white wine and Blue Limberger (Blaufränkisch) red wine (vintage 2013)] were enriched with lignan hydroxymatairesinol originated from spruce knots. These spruce knots with removed resin were extracted with ethyl alcohol of agricultural origin. Ethanol extracts of lignans were then used to enrich wine sorts. Enriched wines were stored for 13 months. At 2, 6, and 13 months, samples were taken and subjected to a variety of analyses and sensory evaluations. Analyses included 7-hydroxymatairesinol and alpha-conidendrin lignan content, antioxidant activity (as determined by FRAP), total polyphenols, and sensory evaluation. The obtained data were evaluated using the analysis of variance to determine which factors e.g. wine type, quantity of added lignan extracts, additional sugar, method of preservation, and storage time had the most significant influence on lignan content, antioxidant activity and polyphenol content. In all cases the lignan content in the wines was significantly influenced by the addition of lignan extracts. After one year of storage, lignan contents changed only moderately and added lignans were stable in stored wines. Total polyphenol content in wines and the antioxidant activity of wines were significantly influenced by the type of wine (i.e., red or white). The presented method of wine enrichment with lignans opens the door for the production of extra quality wines.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3640
Author(s):  
Tomasz Tarko ◽  
Magdalena Januszek ◽  
Aneta Pater ◽  
Paweł Sroka ◽  
Aleksandra Duda-Chodak

Providing yeast with the right amount of mineral salts before fermentation can contribute to improving the entire technological process, resulting in a better-quality final product. The aim of this study was to assess the impact of apple must supplementation with mineral salts ((NH4)2SO4, MgSO4, (NH4)3PO4)) on enological parameters, antioxidant activity, total polyphenol content, and the profile of volatile cider compounds fermented with various yeast strains. Rubin cultivar must was inoculated with wine, cider, and distillery or wild yeast strains. Various mineral salts and their mixtures were introduced into the must in doses from 0.167 g/L to 0.5 g/L. The control sample consisted of ciders with no added mineral salts. The basic enological parameters, antioxidant properties, total polyphenol content, and their profile, as well as the composition of volatile compounds, were assessed in ciders. Must supplementation with magnesium salts significantly influenced the use of the analyzed element by yeast cells and was dependent on the yeast strain. In supplemented samples, a decrease in alcohol concentration and total acidity, as well as an increase in the content of extract and total polyphenols, was observed compared to the controls. The addition of ammonium salts caused a decrease in the amount of higher alcohols and magnesium salts, as well as a decrease in the concentration of some esters in ciders.


2010 ◽  
Vol 46 (4) ◽  
pp. 651-656 ◽  
Author(s):  
Adriana Bramorski ◽  
Adriana da Rosa Cherem ◽  
Chaiana Paula Marmentini ◽  
Joseane Torresani ◽  
Tatiana Mezadri ◽  
...  

The plant Morinda citrifolia L. (noni) has been the focus of many recent studies due to its potential effects on treatment and prevention of several diseases. However, there are few in vivo and in vitro studies concerning its composition and antioxidant capacity. The aim of the present study was to determine the total polyphenol content (TPC) and antioxidant capacity of a juice commercialized as noni juice, but containing grape, blueberry and noni fruits. Commercial noni juice was compared against its separate constituents of blueberry and grape juice. Folin-Ciocalteu and DPPH• methods were used to determine the concentration of total polyphenol content and antioxidant activity, respectively. Commercial noni juice presented higher values of TPC (91.90 mg of gallic acid/100 mL juice) and antioxidant activity (5.85 mmol/L) compared to its 5% diluted constituents. Concentrated blueberry juice presented higher TPC and antioxidant activity than the other juices analyzed. Considering that the blueberry and grape juices account for only 10% in the composition of commercial noni juice, it can be inferred that these two components contribute significantly to the antioxidant activity. Therefore, additional studies are necessary in order to elucidate the contribution of the noni juice as an antioxidant.


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