Novel Coulometric Approach to Evaluation of Total Free Polyphenols in Tea and Coffee Beverages in Presence of Milk Proteins

Ziyatdinova, Guzel; Nizamova, Alfiya; Budnikov, H. C.

doi:10.1007/s12161-010-9174-0

Cited by 31 publications

(14 citation statements)

References 39 publications

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“…Antioxidant parameters can be used for the optimization of extraction of AOs from plant material (spices [71], herbs [39,70]). The statistically significant difference in TAC has been obtained for green and black tea [73], while the FRP for them has been similar due to the presence of albumins in green tea that binds proteins [77]. In the case of cognac and brandy [71], the TAC and FRP are statistically significantly higher for cognacs than for brandies and grow with the age increase for both types of aged distilled beverages.…”

Section: Evaluation Of Total Antioxidant Parametersmentioning

confidence: 84%

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

Ziyatdinova

Budnikov

2021

Chemosensors

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The definition of antioxidants (AOs), their classification and properties as well as electrochemical sensor systems for AOs analysis are briefly discussed. The analytical capabilities of coulometric titration with electrogenerated titrants as sensor systems for AOs determination have been considered in detail. The attention focused on the individual AO quantification that was mainly used in the pharmaceutical analysis and estimation of total antioxidant parameters (total antioxidant capacity (TAC), ferric reducing power (FRP) and ceric reducing/antioxidant capacity (CRAC)) allowing the fast screening of the target samples including their quality control. The main advantages of coulometric sensor systems are pointed out. The selective quantification of individual AO in a complex matrix using a combination of chromatography with coulometric or coulometric array detection under potentiostatic mode is discussed. The future development of coulometric sensor systems for AOs analysis is focused on the application of novel coulometric titrants and the application of coulometric detection in flow injection analysis.

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Section: Evaluation Of Total Antioxidant Parametersmentioning

confidence: 84%

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

Ziyatdinova

Budnikov

2021

Chemosensors

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“…Different additives may influence the performance of these methods in several ways. While milk proteins (casein and bovine serum albumin) formed complexes with polyphenolic constituents in coffee thereby significantly reducing their available OH groups, and thus their antioxidant capacities, as revealed by coulometric titration with hexacyanoferrate (III) ions [ 143 ]; addition of cationic surfactant (cetyltrimethylammonium bromide) in the supporting electrolyte (0.04 mol L −1 phosphate buffer, pH 6.0) significantly enhanced the reduction of caffeine at hanging mercury drop electrode, determined by both differential-pulse polarography (DPP) and SWV [ 144 ]. When the surface of a glassy carbon electrode was modified by the deposition of thin film of 4-amino-3-hydroxynaphthalene sulfonic acid (AHNSA), highly selective electrocatalyzed oxidation of caffeine was achieved leading to its high recoveries in coffee extracts [ 145 ].…”

Section: Methods For Characterization and Quantification Of Bioactmentioning

confidence: 99%

Bioactive Micronutrients in Coffee: Recent Analytical Approaches for Characterization and Quantification

Nuhu

2014

ISRN Nutrition

112

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Production of coffee beans is an important lifeline for the economy of several countries in Latin America, Africa, and Asia. The brew from this well sought for cash crop is readily consumed due to its good sensory qualities owing to the presence of many micronutrients. Some of these chemical compounds possess biological activities, including antiproliferative, antioxidant, and antimicrobial effects. Four representative groups of these micronutrients, namely, caffeine, chlorogenic acid, diterpenes, and trigonelline, play key roles in these bioactive effects of coffee. In order to guarantee the quality of coffee products and to protect consumer interest and safeguard their well-being, it is extremely important to employ sensitive and accurate analytical methods in the characterization and quantitative determination of these bioactive constituents. This review aims to present recent applications in this regard.

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“…The FRAP test has recently adopted electrochemical detection techniques for better sensitivity, accuracy and reproducibility. A new method of coulometric titration was developed, to determine the FRAP value of different antioxidant materials [ 45 ]. In this modified FRAP method, the antioxidant reacts with the coulometric titrants (electrogenerated ferricyanide ions), and the amount of electrical energy consumed for titration up to the final point (when the initial current is resumed) serves as an indicator for the reduction of the antioxidant power [ 46 ].…”

Section: Chemical Tests Determining Antioxidant Activitymentioning

confidence: 99%

Analytical Methods Used in Determining Antioxidant Activity: A Review

Munteanu

Apetrei

2021

IJMS

1,017

527

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The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1 -picrylhydrazyl] (DPPH) test. All these assays are based on chemical reactions and assessing the kinetics or reaching the equilibrium state relies on spectrophotometry, presupposing the occurrence of characteristic colours or the discolouration of the solutions to be analysed, which are processes monitored by specific wavelength adsorption. These assays were successfully applied in antioxidant analysis or the determination of the antioxidant capacity of complex samples. As a complementary method in such studies, one may use methods based on electrochemical (bio)sensors, requiring stages of calibration and validation. The use of chemical methods together with electrochemical methods may result in clarification of the operating mechanisms and kinetics of the processes involving several antioxidants.

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Novel Coulometric Approach to Evaluation of Total Free Polyphenols in Tea and Coffee Beverages in Presence of Milk Proteins

Cited by 31 publications

References 39 publications

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

Analytical Capabilities of Coulometric Sensor Systems in the Antioxidants Analysis

Bioactive Micronutrients in Coffee: Recent Analytical Approaches for Characterization and Quantification

Analytical Methods Used in Determining Antioxidant Activity: A Review

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