Inclusion complexation of catechins by hyperbranched cyclodextrin: preparation, characterization, stability, antioxidant and antimicrobial properties

Abstract

Catechin (C) is a flavonoid natural polyphenol with various biological activities; however, it has poor solubility, stability and oral bioavailability, which greatly limit its application in the food and medical fields. Unlike ordinary cyclodextrins, hyperbranched cyclodextrin (CDP), as a hyperbranched polymer, exhibits several remarkable characteristics, such as a high degree of molecular branching, abundant active ends, and a macromolecular structure with multiple cavities. These features provide CDP with unique advantages in a variety of applications. In this study, catechin/hyperbranched cyclodextrin inclusion complex (catechin/CDP IC) and catechin/β-cyclodextrin inclusion complex (catechin/β-CD IC) were prepared using the freeze-drying method at a molar ratio of 1 : 1. The embedding efficiencies (CEs) of the two inclusion complexes were 83.85% and 64.85% respectively. Structural characterization was carried out via FT-IR, XRD, SEM, DSC and ¹H NMR analyses. Furthermore, the results for solubility, thermal stability, storage stability, sustained-release characteristics, cell viability, antioxidant capacity and antibacterial ability of catechin complexed with CDP were superior to those complexed with β-CD. This study provides potential application value for the further development of catechin-based functional foods and health products.