溶劑在高于其沸點(diǎn)但低于臨界點(diǎn)的溫度區(qū)間內(nèi)，在一定壓力下以液化狀態(tài)存在，我們定義為溶劑的亞臨界狀態(tài)。在此狀態(tài)下利用其相似相溶的物理性質(zhì)，用作生物成分萃取的溶劑為亞臨界萃取溶劑，其萃取工藝稱(chēng)為亞臨界萃取工藝。適合在室溫及更低溫度下萃取和脫溶的溶劑，我們定義為低溫亞臨界溶劑，目前適合工業(yè)生產(chǎn)的低溫亞臨界溶劑主要有丙烷、丁烷、二甲謎、四氟乙烷、液氨5種。用一句話(huà)概括：低溫亞臨界生物萃取工藝是一種低溫低壓高效的物理方法。

Overview of subcritical extraction technology

A solvent exists in a liquefied state at a certain pressure in a temperature interval above its boiling point but below its critical point, which we define as the subcritical state of the solvent. The solvents used for extraction of biological components in this state are subcritical extraction solvents by utilizing their physical properties of similar solubility, and their extraction processes are called subcritical extraction processes. Suitable for extraction and desolvation solvents at room temperature and lower temperatures, we define as low-temperature subcritical solvents, currently there are five main low-temperature subcritical solvents suitable for industrial production: propane, butane, dimethyl enigma (DME), tetrafluoroethane(R134a), and liquid ammonia. Summarized in one sentence: Subcritical extraction process is a low-temperature, low-pressure and high-efficiency physical methods.