Soy sauce brewed by natural sunshine fermentation process and sweet oil fermented by shading and high temperature are usually clarified by precipitation. Natural precipitation can only settle large particulate matter, and can not remove the colloid and other macromolecular impurities that cause soy sauce turbidity, resulting in the phenomenon of turbidity, scaling on the bottle wall and bottom precipitation in the shelf life of bottled soy sauce.
In traditional soy sauce, conical storage tank is used for removing impurity and precipitation, and then more than two times of multi-stage precipitation method or nylon bag frame method is used for natural filtration. These methods have low filtration efficiency and unsatisfactory results. In recent years, some domestic scholars have studied the clarification of soy sauce by ultrafiltration with organic membranes, but the shortcomings are that it is not resistant to high temperature, acid, alkali, organic solvents, easy to plug, easy to be contaminated by microorganisms, low membrane flux and so on. Since 1990s, inorganic ceramic membrane
separation technology has been widely used in food and fermentation fields. The main materials of inorganic ceramic membrane are Ti02 and A1203 with stable properties. These materials are made of inorganic ceramic membrane by sol-gel method. It has a good effect on removing impurities and clarifying soy sauce.
Raw soy sauce - diatomite filtration - ultrafiltration system - sterilization (optional sterilization) – filling
Technical advantages of soy sauce ultrafiltration membrane filtration:
1. Molecular filtration and removal of sediment will not lead to sediment and bacteria exceeding the standard.
2. Bright color prolonged the shelf life of soy sauce.
3. The sterilization effect is good, and the number of colonies is far below the national standard.
4. The cross-flow operation design of the system eliminates the need for adding filter aids to thoroughly solve the problem of pollution blockage.
5. Running at room temperature. Do not change the flavor of soy sauce.
6. Modular design of the system, easy replacement of filter materials, design of online regeneration cleaning and sewage disposal devices, reduce labor intensity and production costs, improve production efficiency.