Precipitation of Green Tea Polyphenols Using a Supercritical Anti-Solvent Process

 

One of the most important components present in green tea are polyphenols. There have been numerous papers published about their health benefits. Due to their antioxidant activity there are numerous fields for their application.

 In this research work, supercritical anti solvent process was used as a process for precipitation of polyphenols from ethanol/water solution, starting form 100 % ethanol to 0 % of ethanol in the initial solution.

In this SAS process supercritical carbon dioxide was used as media to precipitate particles dissolved in a solvent. Schematic presentation of SAS process presented in Figure 1.

By changing different parameters such as pressure, temperature, mass flow and concentration of polyphenols in the initial solution, different powders were produced. Water content was determined with Karl Fisher and composition of powders (polyphenol and caffeine content) with HPLC. Particle morphology was determined with SEM.

Figure 1: Schematic presentation of SAS process