ABSTRACT
Anthocyanins are water-soluble plant pigments, responsible for the red, purple, and blue colors of many fruits, vegetables, cereal grains, and owers. They are of interest to nutritionists because of their postulated health benets, as well as to food processors because of their colorful character as a natural alternative to the use of synthetic dyes. Research concerning their health benets has become prominent since the late 1990s. Up to now, numerous studies have suggested that anthocyanins are protective against many chronic diseases such as dietary antioxidant [1,2], antimutagenic [3,4], and chemopreventive [5-8] nutraceuticals that contribute to reduced incidences of chronic diseases and the prevention of obesity and diabetes [9,10]. These topics are discussed in detail in the following chapters of this book. Research on the metabolic fate and bioavailability of anthocyanins in vivo become crucial for elucidating pharmacokinetics as well as the possible mechanisms of bioactivity. Therefore, accurate and suitable identication and quantication of anthocyanins and their metabolites must be established. This chapter will present an overview of the current knowledge
4.1 Introduction .................................................................................................. 115 4.2 Anthocyanins and Their Biological Metabolites .......................................... 116
4.2.1 Types of Anthocyanins ..................................................................... 116 4.2.2 Anthocyanin Metabolites.................................................................. 118
4.3 Bioavailability ............................................................................................... 120 4.4 Isolation of Anthocyanins or Anthocyanin Metabolites from
Biological Samples ....................................................................................... 122 4.4.1 Pretreatment ...................................................................................... 122 4.4.2 Purication ....................................................................................... 122
4.5 Detection .......................................................................................................124 4.5.1 HPLC-PDA Detection......................................................................124 4.5.2 Mass Spectrometer Detection ........................................................... 126 4.5.3 NMR Spectroscopy .......................................................................... 129 4.5.4 Other Analytical Tools ..................................................................... 131
4.6 Conclusions ................................................................................................... 131 References .............................................................................................................. 132
of how anthocyanin chemistry affects their stability and the chemistry of their metabolites, as well as their bioavailability. More specically, we will discuss some of the challenges of evaluating anthocyanins in biological samples as well as the different methodologies available for the analysis of anthocyanins and their metabolites in biological samples, including blood, urine, and different tissues or uids.
