Measurement of antioxidant activity

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

https://www.mdpi.com/1422-0067/22/7/3380/pdf

Analytical Methods Used in Determining Antioxidant Activity: A Review.

https://isiarticles.com/bundles/Article/pre/pdf/52481.pdf

Determination of DPPH free radical scavenging activity: application of artificial neural networks.

Characterization and antioxidant activities of extracellular and intracellular polysaccharides from Fomitopsis pinicola

Antioxidants play a pivotal role in food preservation and health promotion. Antioxidant activity can be measured by a variety of methods that include hydrogen atom transfer (HAT) and single electron transfer (ET), reducing power, and metal chelation, among others. While chemical assays may be employed in the initial screening of antioxidants based on their intrinsic activity, model systems are widely used for further determination of antioxidant potential in specific applications related to food protection or in reducing oxidative damage in biological systems or in the body. Understanding the principle mechanisms, advantages, and limitations of the measurement assays is important for proper selection of methods or combination of methods for assessing antioxidant activity, which is, in turn, important for proper evaluation of antioxidant potential in desired applications. This chapter provides an overview of methods available for assessing antioxidant activity in food and biological systems.

Methods for the assessment of antioxidant activity in foods

A novel high throughput method based on the DPPH dry reagent array for determination of antioxidant activity.

An optical fiber formaldehyde biosensor based on a modified single sol–gel film consisting of alcohol oxidase (AOX) and chlorophenol red (CPR) was developed. The modification relies on addition of poly(vinyl alcohol) (PVA) into sol–gel matrix, in order to increase the function of AOX. The biosensing element on a sol–gel film has been placed inside the flow-cell for the flow system measurements. In the presence of a constant AOX, a color change of the CPR was measured in term of its reflected signal intensity at the wavelength 555 nm. This color change could be related to the formaldehyde concentration in the sample solutions. The performance of optical formaldehyde biosensor in the flow system has been optimized. The formaldehyde biosensor exhibited a dynamic linear response range in the formaldehyde concentration range of 0–10 mg/L with linear correlation (r ) was 0.996. The detection limit of the biosensor was 0.035 mg/L while reproducibility was < 1% RSD (relative standard deviation). Tofu as real food sample were analysis using the biosensor revealed that it was promising for food analysis of formaldehyde.

http://www.researchgate.net/profile/Bambang_Kuswandi/publication/263094618_An_Optical_Fiber_Formaldehyde_Biosensor_Based_on_a_Modified_Single_SolGel_Film_of_Alcohol_Oxidase_and_Chlorophenol_Red_in_Flow_System/links/5444747d0cf2a6a049ab0e48.pdf

An Optical Fiber Formaldehyde Biosensor Based on a Modified Single Sol-Gel Film of Alcohol Oxidase and Chlorophenol Red in Flow System

Proceeding of International Conference on Halal Science & Technology 2012 – HALALSTECH+ 2012, DENPASAR, BALI, INDONESIA JULY 4-6, 2012

M. Amrun Hidayat

Papers

A novel high throughput method based on the DPPH dry reagent array for determination of antioxidant activity.

An Optical Fiber Formaldehyde Biosensor Based on a Modified Single Sol-Gel Film of Alcohol Oxidase and Chlorophenol Red in Flow System

The Development of Paper based Biosensor for Formaldehyde Detection in Food Samples