At the start of this project we confronted the question of why write yet another book on antioxidants and why now? It is our view that there is a compelling need to provide a balanced view on the topic of antioxidants and antioxidant activity along with an imperative to dispel misconceptions on these issues. This book provides a new and critical approach to antioxidant testing and questions existing methodology and outcomes. It will challenge readers to re-think their approach to antioxidant measurements.

Why is this necessary? The Journal of Food Composition and Analysis has banned papers that employ antioxidant and total phenolic assays. Food Chemistry has placed restrictions on their publication, taking a more balanced approach and emphasizing the importance of colorimetric methods when combined with state-of-the-art techniques. The latter journal has recently published an article titled “Antioxidant activity, total phenolics and flavonoids contents: Should we ban in vitro screening methods?”

The controversy surrounding antioxidant activity measurements provides the reason and central unifying theme of this book. This theme permeates the entire book. It leads to some obvious questions such as why perform an activity measurement? In what circumstances is such a measurement valid? What problems arise (i.e. interferences, side reactions, etc.)? Providing readers with this information will assist them to navigate this contested space. The book provides a clear and logical presentation of why antioxidant measurements remain as critical and valid now as they were previously. We are not seeking to “pull the various factions together”. Assuming there are those that think all things antioxidant are good, and those that think any antioxidant testing is a waste of time, we propose to show that it is the context of antioxidant testing that is critical, and that choosing the appropriate methodology should be the focus.

There are several reasons for measuring antioxidant activity, one of which is the prediction of the impact of an antioxidant on health. This application has not been particularly successful, and Journal of Agricultural and Food Chemistry has published a paper titled “Antioxidants: Differing meanings in food science and health science” presumably in an attempt to bridge the gulf between the two areas. This paper concluded that the “term antioxidant is a very useful term in food science. The antioxidants in food items help to prevent oxidative reactions that decrease the quality of the foods. However, this cannot be extrapolated to the biomedical sciences, and the term antioxidants does not equate to health benefits”. The implication here is that the term antioxidant is not very useful in health science as it does not equate to health benefits and yet antioxidants generally perform an excellent function in maintaining homeostasis and oxidative balance. It follows that the term is very useful in health science when used appropriately (and hence we need to be able to measure it). The problem is not with the term antioxidant, but with those who have endeavored to equate health and antioxidant (activity). When used inappropriately, good data become poor quality data. However, we must not condemn the data or the measurement because of inappropriate use. Many researchers in this area do not have an adequate chemistry background to make this distinction. This book addresses this need.

Although a single substance may and will exhibit several different antioxidant activities depending, for example on the substrate, the term antioxidant activity is the same whether dealing with food science or health science; it is the ability of a substance to inhibit oxidation in a particular circumstance. Different branches of science may wish to qualify this ability by adding qualifiers such as the nature of the substrate, etc., but this does not alter the unifying definition.

The very small trickle of negative papers plus the understandable actions of some journals has probably confused many people who are using activity measurements in an appropriate context for very valid reasons. This book provides what is needed to overcome the confusion by placing matters in a correct perspective together with an emphasis on a strong “chemistry” foundation.

By directly addressing the current controversies about antioxidant testing the book captures the new and developing wave of thinking about antioxidants (their role, value and measurement) in its infancy and establishes antioxidants and activity measurements in a proper balanced perspective.

The book is new from several perspectives. It brings together a range of disparate topics that has not been done previously. Topic coverage is broader than other texts and includes areas not normally covered in comparable texts including accelerated testing methods, lab-on-a-chip and chemometrics. The language and approach (e.g. schematic outline of chapters) are designed specifically to facilitate a deeper understanding of the topic and to assist readers to navigate the complexities and confusion inherent in this area.

The publication of this book is timely; indeed, there has never been a more important or appropriate time for its publication for the reasons already detailed. This book is ambitious and comprehensive and challenges current thinking in an area that is both extremely hot (based on the growing number of publications annually) and also extremely controversial. The book approaches the topic from a totally different angle producing new perspectives on antioxidant activity measurements.

There is an inevitability of overlap of content in an edited book. This is particularly desirable in a book on a contentious and controversial topic such as antioxidants. It provides a diverse view that hopefully will facilitate readers in forming and developing their own ideas. Authors have thus been granted considerable leeway in deciding content and expressing views but within the overall prescribed framework. The ultimate goal of the book is the development and application of methods appropriate to the different samples and questions to which readers require answers in their diverse fields of research and practice.

Finally, as a student in 1970 I (K.R.) was fascinated by the molecular models of the synthetic antioxidants, BHA and BHT, and the ability to predict and explain the differences in infrared spectra of the two compounds (see the front cover) based on the reduction in the extent of intermolecular hydrogen bonding in BHT. This stimulated a lasting interest in structure–activity relationships that continues in 2020.

Paul D. Prenzler

Danielle Ryan

Kevin Robards