Micromechanism of ultrahigh pressure extraction of active ingredients from green tea leaves

Ultrahigh pressure extraction (UPE), as a promising novel technique, has exhibited great potential for extracting bioactive ingredients from plant materials. The objective of this work was to investigate the micromechanism of UPE of active ingredients from green tea leaves. The microstructure and ultrastructure of the untreated green tea leaves samples and UPE samples will be examined by SEM and TEM, and the micromechanism of UPE of active ingredients from green tea leaves will be discussed. SEM micrographs and TEM micrographs revealed that ultrahigh pressure could result in the disruption of the leaves tissue, cellular wall, membrane and organelles, which enhanced the mass transfer of the solvents into the leaves materials and the soluble constituents into the solvents. This work could help better utilize plant materials to obtain biologically active compounds as a readily accessible source for pharmaceutical usage. (C) 2011 Elsevier Ltd. All rights reserved.