Fermented brown bean paste is a seasoning, primarily made from soybeans and black beans, with additional ingredients such as chili, sesame oil, and salt. It falls under the category of fermented red-brown seasonings. To cater to different consumer preferences, various ingredients like sesame oil, soybean oil, monosodium glutamate, and chili are added during production, expanding the variety of the paste and making it widely beloved.

Traditional soybean paste made through traditional methods undergoes a natural fermentation process, during which a brine circulation takes place in the fermentation pond. This results in the soybean paste containing a higher salt content as it naturally develops its aroma.

Utilize electro dialysis technology to reduce the salt content in traditional Douban sauce from over 18% to 6-8%; while doing so, maintain the sauce's aroma, ensuring the maximum preservation of organic matter and aromatic substances within the Douban sauce.

The entire process maintains the traditional fermentation without altering it, ensuring that the sauce aroma, nutrients, and flavor compounds remain unchanged. Moreover, the extracted salt can be reused, thus not increasing the environmental pressure. Therefore, this process qualifies as a green and environmentally friendly upgrading technology.

During the direct consumption or cooking process, using low-sodium Douban sauce can increase the usage of the sauce without adding extra salt intake. It enhances the flavor quality of the dish for the consumers, and boosts the sales volume for manufacturers.