What are the main membrane separation methods of food separation technology now?

Clarification by microfiltration membrane:

The retention characteristics of microfiltration membrane are characterized by the pore size of the membrane, which is usually in the range of 0. 1- 1 micron, so microfiltration membrane can separate large-diameter bacteria and suspended substances, but its ability to remove protein is very weak. In food separation technology, it is generally used for clarification and filtration of feed liquid and removal of suspended solids, and it is usually used for cold sterilization in dairy industry.

Ultrafiltration membrane refining:

The retention characteristics of ultrafiltration membrane are characterized by the molecular weight of standard organic matter, which is a membrane process between microfiltration and nanofiltration. Generally, the molecular weight cut-off range is 65,438+0,000–300,000. Therefore, ultrafiltration membrane can separate protein, bacteria, colloid, polypeptide and other macromolecular organic substances. It is also widely used for clarification of feed liquid, separation and purification of macromolecular organic matter, and heat removal.

Concentration and desalination of nanofiltration membrane;

The retention characteristics of the membrane are characterized by the retention rates of standard NaCl, MgSO4 _ 4 and CaCl2 _ 2 solutions, which are usually between 60% and 99%. It is a membrane separation technology between ultrafiltration and reverse osmosis, and the corresponding molecular weight retention range is150–1000, and the pore size is several nanometers, so it is called nanofiltration. So nanofiltration membrane can treat oligosaccharides, food additives, natural and natural products.

Reverse osmosis membrane concentration technology;

The interception object of the membrane is all ions, only water is allowed to pass through the membrane, and the effluent is deionized water. Reverse osmosis is mainly used in food industry to produce pure water and concentrated small molecular products.