8 - Nanoencapsulation of Green Tea Polyphenols

Abstract

Globally, tea is the most consumed beverage; next only to water. Compared to black or oolong tea, various in vivo and in vitro studies have confirmed that green tea carries a rich profile of components responsible for antimutagenic, antidiabetic, antiinflammatory, antibacterial, and antiviral properties and the potential to lower the risk of cancer and cardiovascular diseases. However, most of these are polyphenols, including catechins are known to have poor stability to temperature, light, pH, and the presence of oxygen or metal ions. Micro- and nanoencapsulation of polyphenols can protect these valuable components from degradation. It also serves added benefits in terms of flavor-masking, controlled/targeted release and improving bioavailability of polyphenolic compounds. This chapter presents an elaborate note on various encapsulation techniques, with emphasis on nanoencapsulation. Though the basic idea involves entrapment of bioactive compounds within a protective shell of 10–200nm diameter, there have been numerous research challenges and developments in this field. These are discussed in addition to techniques for the production of colloidal nanoparticle dispersions and suspensions. The scope of incorporating these encapsulated bioactive compounds in other food products is also presented.