Determination of antioxidant activity, rutin, quercetin, phenolic acids and trace elements in tea infusions: Influence of citric acid addition on extraction of metals

2015 ◽  
Vol 40 ◽  
pp. 70-77 ◽  
Author(s):  
Magdalena Jeszka-Skowron ◽  
Magdalena Krawczyk ◽  
Agnieszka Zgoła-Grześkowiak
Keyword(s):  
Antioxidant Activity ◽  
Trace Elements ◽  
Citric Acid ◽  
Phenolic Acids ◽  
Acid Addition ◽  
Tea Infusions ◽  
Extraction Of Metals

Polyphenols, tannins and caffeine content and antioxidant activity of green teas coming from organic and non-organic production

2013 ◽  
Vol 30 (3) ◽  
pp. 263-269 ◽  
Author(s):  
Renata Kazimierczak ◽  
Ewelina Hallmann ◽  
Anna Rusaczonek ◽  
Ewa Rembiałkowska
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Acids ◽  
High Performance ◽  
Production Systems ◽  
Organic Production ◽  
Appreciable Effect ◽  
Total Polyphenols ◽  
Total Polyphenol ◽  
Tea Infusions ◽  
Exposed Surface Area

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.

Determination of free phenolic acids and antioxidant activity of methanolic extracts obtained from fruits and leaves of Chenopodium album

2011 ◽  
Vol 126 (4) ◽  
pp. 1850-1855 ◽  
Author(s):  
Abdul Hafeez Laghari ◽  
Shahabuddin Memon ◽  
Aisha Nelofar ◽  
Khalid Mohammed Khan ◽  
Arfa Yasmin
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Acids ◽  
Chenopodium Album ◽  
Methanolic Extracts ◽  
Free Phenolic Acids

scholarly journals Effect of ‘Jamblang’ (Syzygium cumini) Peel and Citric Acid Addition on Antioxidant Activity of ‘Kolang-kaling’ Jam

2018 ◽  
Vol 17 (3) ◽  
pp. 140-145 ◽  
Author(s):  
Tuty Anggraini ◽  
Yulita Kurniawan ◽  
Rina Yenrina ◽  
Kesuma Sayuti
Keyword(s):  
Antioxidant Activity ◽  
Citric Acid ◽  
Syzygium Cumini ◽  
Acid Addition

scholarly journals Concentration of Pro-Health Compound of Sorghum Grain-Based Foods

Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 216
Author(s):  
Jakub Frankowski ◽  
Anna Przybylska-Balcerek ◽  
Kinga Stuper-Szablewska
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Acids ◽  
Total Content ◽  
Total Phenolic ◽  
Antioxidant Compounds ◽  
Main Ingredient ◽  
Qualitative And Quantitative ◽  
Sorghum Grains ◽  
Sorghum Grain

More than 35% of the world sorghum seed production is a human food source. The main ingredient of fully ripe sorghum grains is starch. Sorghum does not contain gluten, and it is also a rich source of antioxidant compounds other than vitamins or macro- and microelements, including phenolic acids, flavonoids, and sterols. The aim of this study was to determine the antioxidant activity and the content of selected bioactive compounds, i.e., total phenolic acids, total flavonoids, and total phytosterols, as well as determination of the qualitative and quantitative profile of phenolic acids, flavonoids, and phytosterols in various food products, the basic ingredient of which was sorghum grain. It was found that antioxidant activity is related to the total phenolic compounds content. The ABTS•+ ranged from 319 to 885 µmol TROLOX/kg. However, white sorghum grain flour contained almost two times more polyphenols than red sorghum grain flour. The FPA ranged from 224 in raw pasta to 689 mgGAE/100 g in white sorghum grain. During this study, the quantitative profile of selected polyphenols in grain flour, wafers, pasta, and cookies containing sorghum grain was also investigated, as well as the content of 11 selected phenolic acids. Total content of the latter ranged from 445 to 2850 mg/kg. Phytosterols such as beta-sitosterol, campesterol, and stigmasterol were found in all the analyzed products. Based on this research, it was investigated that the products containing sorghum grains can be classified as functional food.

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