Micro-mechanism analysis of ultrahigh pressure extraction from green tea leaves by numerical simulation

Ultrahigh pressure extraction (UPE) technique displays great advantages in natural products extraction. According to literature, compared to conventional methods, UPE shows the significant advantages of less time consuming, higher extraction yields, less solvent consumption, higher purity of product. Moreover, UPE minimizes the heat generation which contributes to thermal degradation on bioactive components. So UPE has been considered to be a promising technique on extracting bioactive ingredients from biological material. Recent research declared that the high extraction efficiency of UPE should be attributed to disruption of cellular organelle, which causes enhancement of diffusion and mass transfer. The aim of this work is to explore the micro-mechanism of cell disruption and mass transfer across cell membrane when UPE works. Attempting finite element method, it showed that strain and stress concentration occurred on the organelle membrane under high hydrostatic pressure. The results might reveal the deformation of cellular structure, formation and development of cell failure. It helps establish mechanism model of cell disruption and mass transfer. In addition, it was found that cell with irregular shape performed higher sensitivity to pressure in simulation analysis. This result might provide new ideas in technique improvement.