The invention discloses a method for refining
papain, which comprises the following steps: preparation of pawpaw puree; pretreatment; milling; heat exchange; two stages of
centrifugation; micro-
filtration; hyperfiltration;
freeze drying in vacuum; pulverization and modulation; and preparation of a finished product. The extraction method is characterized in that: (1) by carrying out the pretreatment and the heat exchange and keeping an extraction process being carried out under a low-temperature condition, the influence on activity reduction of the
papain under the conditions of high temperature for a long time, and the like can be effectively reduced; (2) by milling, the
papain can be sufficiently dissolved in material liquid so as to be beneficial to improving the extraction and
recovery ratio of the papain; (3) the papain extracted by the method has high purity and activity (the highest activity can reach 3,000,000u / g) and good
thermal stability; indexes such as appearance, rationalization, microbial limit, and the like can reach or exceed relevant food and
medicine standards at home and abroad; by modulation, products in different specifications can be produced and widely applied to the industries and the fields of medicinal health products, foods,
cosmetics, chemical leather manufacture, and the like; and (4) the method has simple process, low production cost, high yield and industrial production.