Green tea encapsulation by means of high pressure antisolvent coprecipitation

In this work, green tea polyphenols were coprecipitated with a biodegradable polymer (poly-ε-caprolactone, MW: 25,000) by a semi continuous supercritical antisolvent process (SAS). Carbon dioxide was used as antisolvent in addition to be a dispersing agent. Green tea extracts were obtained by microwaved assisted extraction (MAE) technique with acetone. The influence of different process parameters, including the operating pressure (8-12 MPa) and temperature (283-307 K), the polymer to solutes concentration (w/w) ratio (4-58), and the CO2 to solution mass flow rate ratio (4-10) have been studied experimentally. Total content of polyphenols, quantified according to the Folin-Cicalteu method, showed concentrations from 60 to 100% of the maximum theoretical composition. Also HPLC analyses were performed to verify the presence of some of the major tea catechins. SEM images of the products show small particles (3-5 μm) with narrow particle size distribution with a high degree of agglomeration. Drug release profiles in phosphate buffer (pH = 6.8) reveal that the majority of catechins are encapsulated in the crystalline domains of the polymer. © 2010 Elsevier B.V.Fil: Sosa, M. V.. Universidad de Valladolid; España. Universidad Nacional de Rio Cuarto. Facultad de Ingeniería. Departamento de Tecnología Química; ArgentinaFil: Rodríguez Rojo, S.. Universidad de Valladolid; EspañaFil: Mattea, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Valladolid; EspañaFil: Cismondi Duarte, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Cocero, María José. Universidad de Valladolid; Españ