Cold plasma pretreatment technology for enhancing the extraction of bioactive ingredients from plant materials: A review

In the process of extracting bioactive ingredients from plant materials, the main resistance to the diffusion of bioactive ingredients into the solvent is cell wall structure of plant materials. The cold plasma, whose temperature of the whole system is close to or slightly higher than the room temperature, has been widely used as a treatment technology prior to extraction due to the advantages of low temperature, high efficiency, low energy consumption, environmental friendliness, and so on. It can effectively disrupt cell wall structure, increase surface hydrophilicity of plant materials, and thus significantly improve the extraction efficiency of plant bioactive ingredients. The current review gives a detailed overview of cold plasma pretreatment technology in order to provide valuable information for scholars who are interested in this field. The structures of dielectric barrier discharge (DBD) and glow discharge plasma generation system are introduced, respectively. The enhanced mechanism of the high efficiency is discussed in detail. Several critical factors such as working gas, output power/output voltage, treatment time, soaked/dried raw materials are fully analyzed. Recent applications on the extraction of various bioactive ingredients are listed and discussed. Finally, its future development is prospected.