Green tea encapsulation by means of high pressure antisolvent coprecipitation

SOSA, M. V.; RODRÍGUEZ-ROJO, S.; MATTEA, F.; CISMONDI DUARTE, M.; COCERO, M. J.

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Año: 2011 vol. 56 p. 304 - 311

0896-8446

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.