Preface

Anthocyanins are an important class of natural compounds that are abundant in fruits such as berries and vegetables. Their health-promoting benefits and colorant properties are of interest to commercial industries, with exciting applications for the health sector, the cosmetic, agricultural, chemical, and food industries. There are various methods that can be used to extract anthocyanins from natural sources, including conventional solvent-based techniques and assisted technologies that can improve the extraction yield. From an environmentally sustainable viewpoint, there is potential for extracting anthocyanins from food processing byproducts, which can be an attractive option for food manufacturers as a means of reducing disposal costs and generating additional revenue. The use of anthocyanins as dyes, natural colorants, and health-promoting ingredients has attracted a lot of interest from researchers and industry. However, the chemistry of anthocyanins is quite complex as anthocyanins exist in a multistate system, where the pH of the system determines the chemical form and the color that dominates. It is therefore necessary to understand anthocyanin interactions with the environment so that effective in vitro and in vivo applications can be realized.

Recent research has revealed more insight into the fate of anthocyanins in the body, which is essential in formulating stable anthocyanin systems for health-related applications, such as functional food ingredients and nutritional supplements. Although it was once assumed that anthocyanins are poorly absorbed, recent studies have revealed significant absorption of microbial-derived anthocyanin metabolites, resulting in a much higher bioavailability than previously thought. In addition, researchers have shown that the stomach, as well as the small intestine, has an important role in the absorption of anthocyanins. It has also been shown that it is not the amount, but rather the frequency of ingestion that impacts their absorption. Therefore, controlled release systems to modulate anthocyanin release and absorption are an exciting field with potential applications in functional foods and nutritional supplements for targeted delivery.

This book has been motivated by the current gap that exists between what is known about the fate of anthocyanins in the body (pharmacokinetics) and the research related to controlled release systems. These fields are often divided between pharmaceutical sciences and food engineering/technology. As natural health compounds, anthocyanins and anthocyanin-rich extracts are not as well-defined as pharmaceutical drugs; therefore, designing appropriate controlled release systems is difficult without this knowledge. Thus, the objective of this book is to bring together researchers from different fields who will discuss the extraction of anthocyanins from natural sources, their health-promoting properties, pharmacokinetics, and controlled release systems that can modulate the release of these compounds for application in functional foods and nutritional supplements. This book is unique in its discussion of diverse research areas related to anthocyanins and their potential applications that are seldom brought together for consideration.

The book is organized into four parts:

Part I – Chemistry and Extraction of Anthocyanins. Here, J. Zhang, G. B. Celli, and M. S. Brooks have contributed Chapter 1 based on natural sources of anthocyanins, with emphasis on research published in the past two decades, including examples from traditional Chinese and Indian medicine and what might be considered as “exotic” plants. This is followed by Chapter 2 on the chemistry of anthocyanins by F. Pina, A. J. Parola, M. J. Melo, J. C. Lima, and V. de Freitas, where the reversible multistate anthocyanin system is discussed. Chapter 3 focuses on the extraction methods and commercial considerations for the extraction of anthocyanins from natural sources and is provided by J. Zhang, R. Singh and S. Y. Quek. The potential for using food processing byproducts for the extraction of anthocyanins is explored by N. Brunton in Chapter 4.

Part II – Health Benefits and Metabolism, in which the health benefits of anthocyanins are discussed in Chapter 5 by H. P. V. Rupasinghe and N. Arumuggam. Chapter 6 follows, and recent research into the pharmacokinetics of anthocyanins and its paradigm shift and focus on microbial-driven pharmacokinetics are examined by C. D. Kay and A. Crozier_. Then, the stability and absorption of anthocyanins in the mouth and the role of the stomach in anthocyanin absorption are discussed by G. T. Sigurdson and M. M. Giusti in Chapter 7 and S. Passamonti in Chapter 8, respectively.

Part III – Controlled Release Systems for Anthocyanins, the third part of the book examines controlled release systems, with Chapter 9 by F. P. Flores and F. Kong outlining encapsulation techniques, and then Chapter 10, contributed by G. B. Celli and M. S. Brooks, exploring suitable controlled delivery systems for targeted release of anthocyanins.

Part IV – Conclusions. Chapter 11 includes closing remarks and covers future prospects.

We would like to thank all the chapter contributors who have given so generously of their time and expertise. Thanks also to our families who have supported us throughout this project. We hope that this book will provide a useful, up-to-date resource to readers from various backgrounds who are interested in anthocyanins and their potential applications.

Marianne Su-Ling Brooks

Giovana B. Celli