Pressurized Gas eXpanded (PGX) drying of lysozyme and its composites

Enzymes are natural catalysts capable of catalyzing specific reactions and versatile enough for widespread applications in the industry. To preserve the enzyme’s activity, it is essential to isolate and dry them from aqueous solutions without degrading their structure or making their active sites inaccessible. The Pressurized Gas eXpanded (PGX) liquid technology is a novel process that was successfully used to dry, purify, and micronize various biopolymers from aqueous solution. In this process, a pressurized mixture of CO2 and ethanol (the PGX liquid) at mild temperature is used as the drying medium generating open-porous structures and particles of low bulk density and large specific surface area (SSA). Since the PGX technology has not been previously used to process enzymes, this study was conducted to investigate if the PGX technology could be used for drying enzymes and if the PGX enzymes were still active once they were rehydrated.