Measurement of Antioxidant Activity and Capacity

A comprehensive reference for assessing the antioxidant potential of foods and essential techniques for developing healthy food products

Measurement of Antioxidant Activity and Capacity offers a much-needed resource for assessing the antioxidant potential of food and includes proven approaches for creating healthy food products. With contributions from world-class experts in the field, the text presents the general mechanisms underlying the various assessments, the types of molecules detected, and the key advantages and disadvantages of each method. Both thermodynamic (i.e. efficiency of scavenging reactive species) and kinetic (i.e. rates of hydrogen atom or electron transfer reactions) aspects of available methods are discussed in detail.

A thorough description of all available methods provides a basis and rationale for developing standardized antioxidant capacity/activity methods for food and nutraceutical sciences and industries. This text also contains data on new antioxidant measurement techniques including nanotechnological methods in spectroscopy and electrochemistry, as well as on innovative assays combining several principles. Therefore, the comparison of conventional methods versus novel approaches is made possible. This important resource:

• Offers suggestions for assessing the antioxidant potential of foods and their components

• Includes strategies for the development of healthy functional food products

• Contains information for identifying antioxidant activity in the body

• Presents the pros and cons of the available antioxidant determination methods, and helps in the selection of the most appropriate method

Written for researchers and professionals in the nutraceutical and functional food industries,academia and government laboratories, this text includes the most current knowledge in order to form a common language between research groups and to contribute to the solution of critical problems existing for all researchers working in this field.

Autorentext

About the editors

Resat Apak is Professor of Analytical Chemistry Division, Department of Chemistry, Faculty of Engineering, Istanbul University, Turkey.

Esra Capanoglu is Associate Professor at the Food Engineering Department, Faculty of Chemical
and Metallurgical Engineering, Istanbul Technical University, Turkey.

Fereidoon Shahidi is a University Research Professor at the Department of Biochemistry, Memorial University of Newfoundland, St. John's, Canada.

Inhalt

List of contributors xi

**1 Nomenclature and general classification of antioxidant activity/capacity assays 1
**Yong Sun, Cheng Yang, and Rong Tsao

1.1 Introduction 1

1.2 Nomenclature of antioxidant activity/capacity assays 2

1.3 Classification of antioxidant activity/capacity assays 2

1.4 Conclusions 15

References 15

2 Assays based on competitive measurement of the scavenging ability of reactive oxygen/nitrogen **species 21
**Dejian Huang and Restituto Tocmo

2.1 Introduction 21

2.2 Kinetics is more important than thermodynamics when it comes to scavenging ROS 22

2.3 Peroxyl radical scavenging capacity assay based on inhibition of lipid autoxidation 23

2.4 Application of molecular probes for quantification of antioxidant capacity in scavenging specific ROS/RNS 26

2.5 Conclusion: a unified approach for measuring antioxidant capacity against different ROS? 35

Acknowledgment 36

References 36

**3 Evaluation of the antioxidant capacity of food samples: a chemical examination of the oxygen radical absorbance capacity assay 39
**Eva Dorta, Eduardo Fuentes?]Lemus, Hernan Speisky, Eduardo Lissi, and Camilo Lopez?]Alarcon

3.1 Introduction 39

3.2 Chemical assays to evaluate the antioxidant capacity of food samples 41

3.3 Chemical examination of the ORAC assay: advantages and drawbacks 46

3.4 Future perspectives to improve the antioxidant capacity evaluation of food samples 50

3.5 Conclusions 52

Acknowledgments 52

References 52

4 Electron transfer?]based antioxidant capacity assays and the cupricion reducing antioxidant capacity (CUPRAC) assay 57
**Resat Apak

4.1 Introduction 57

4.2 ET?]based TAC assays 58

4.3 CUPRAC assay of antioxidant capacity measurement 64

References 71

**5 The ferric reducing/antioxidant power (FRAP) assay for non?]enzymatic antioxidant capacity: concepts, procedures, limitations and applications 77
**Iris F.F. Benzie and Malegaddi Devaki

5.1 Introduction: concepts and context 77

5.2 The ferric reducing/antioxidant power (FRAP) assay: a brief overview 79

5.3 Working concepts, what results represent, potential interferences, and limitations 80

5.4 Method outline and detailed procedures for manual, semi?]automated, and fully automated modes 83

5.5 Technical tips for the FRAP assay 89

5.6 Issues of standardization (calibration) and how results are expressed 93

5.7 Issues of sample handling, storage, and extraction 94

5.8 Modifications to the FRAP assay 94

5.9 Illustrative applications 99

5.10 Cautions and concluding remarks 99

Acknowledgments 102

References 102

Further Reading 104

**6 FolinCiocalteu method for the measurement of total phenolic content and antioxidant capacity 107
**Rosa M. Lamuela?]Raventos

6.1 Introduction 107

6.2 Is the FolinCiocalteu method an antioxidant assay? 107

6.3 FolinCiocalteu assay to quantify phenolic compounds 108

6.4 FolinCiocalteu index in wines 109

6.5 Improving the method: more sustainability, less time, and lower cost 110

6.6 Beneficial effects of polyphenols measured by the FolinCiocalteu assay in human biological samples: a biomarker of polyphenol intake 114

References 114

7 ABTS/TEAC (2,2?]azino?]bis(3?]ethylbenzothiazoline?]6?]sulfonic acid)/ TroloxR?]Equivalent Antioxidant **Capacity) radical scavenging mixed?]mode assay 117
**Antonio Cano and Marino B. Arnao

7.1 Introduction 117

7.2 Use of ABTS as a sensor of antioxidant activity: the TEAC assay 119

7.3 Advantages and disadvantages 125

7.4 TEAC assay in hyphenated and high?]throughput techniques 126

7.5 TEAC in pure compounds 128

7.6 TEAC in foods 130 7.7 Future...