Soy sauce, also known as clear sauce, sauce extract, soy oil, or sundried soy sauce, is a traditional Chinese condiment. The brewing process was already mastered by the Chinese people several thousand years ago. Soy sauce is made from plant proteins and starches as main raw materials, undergoing complex biochemical reactions such as microbial fermentation to produce a condiment with unique color, aroma, taste, and rich nutritional value. Its main nutrients include amino acids, soluble proteins, sugars, and organic acids. Soy sauce enhances and improves the flavor of dishes, and also adds or modifies their color.

After thousands of years of development, soy sauce brewing technology has become increasingly mature. However, the soy sauce industry still faces a common problem: the treatment of soy sauce sediment. Soy sauce sediment refers to the precipitated portion remaining after settling of finished or semi-finished soy sauce and removal of the supernatant. It accounts for about 10% of the total soy sauce volume, has a complex composition, relatively high acidity, and contains proteases produced during the koji-making process that are difficult to utilize and cannot be recovered for re-fermentation. Therefore, how to recycle and utilize soy sauce sediment has become a challenge that the soy sauce industry needs to overcome.

Existing methods for treating soy sauce sediment generally use a diaphragm filter press for direct filtration, or add 1% diatomaceous earth, stir evenly in a circulation tank, prefilter to form a filter cake of diatomaceous earth on the filter cloth, and then perform pressure filtration. However, because soy sauce sediment is the product of soy sauce settling, it has a high protein content and a viscous consistency, making it easy to clog the filter cloth, resulting in very low filtration efficiency. Although adding diatomaceous earth improves the filtration speed to some extent, the protein precipitate still clogs the filter cake formed by diatomaceous earth, so filtration efficiency remains low. Moreover, the filter residue contains diatomaceous earth, which cannot be reused and, if discharged, causes environmental pollution. Some technologies involve enzymatic hydrolysis of the tank bottom material before pressure filtration, but the treatment process is complex and costly.

Therefore, research into a process that can quickly filter soy sauce sediment is especially necessary.

Guochu Technology (Xiamen) Co., Ltd., based on years of research in the field of novel separation technologies, has successfully overcome the challenge of recycling soy sauce sediment by applying innovative separation technology. The company can efficiently process soy sauce sediment and recover soy sauce from it. During processing, clogging due to high protein content does not occur, and the operation is stable, with good filtrate quality. No filter aids are required, the filter residue has utilization value, and the recovery rate is very high. This fundamentally solves the problem of soy sauce sediment treatment.

Guochu Technology has successfully applied this novel separation technology to the recovery of soy sauce from sediment, turning waste into treasure by recovering highquality soy sauce products from tank bottom waste, thus solving a major problem in the condiment industry. Moreover, for the soy sauce industry, Guochu Technology has developed a series of new, specialized separation technologies applicable to soy sauce products, including soy sauce desalination, soy sauce concentration, and soy sauce oil removal, addressing various technical challenges in the soy sauce industry.

Guochu Technology (Xiamen) Co., Ltd. is continuously dedicated to the application and promotion of novel membrane separation technologies. With extensive experience in applying specialty membranes in industries such as pharmaceuticals, chemicals, food, beverages, petroleum, petrochemicals, and nuclear energy, the company can develop customized technologies and equipment tailored to customers‘ specific separation requirements.