1. Soak salted fish in brackish water, and the high-concentration salt in salted fish permeates into the low-concentration brackish water. Salted fish will absorb water after soaking in water, so it will become weak.

2. Desalination of brackish water: The salted fish is soaked in brackish water with a concentration of 2%, and the high-concentration salt in the salted fish penetrates into the low-concentration brackish water by using the concentration difference between the two. Soak for about 2-3 hours, take out the salted fish and rinse it with clear water so that the salted fish is not so salty.

Extended data:

First, salted fish:

Salted fish are salted fish and dried fish. Fish used to rot easily because there was no low-temperature preservation technology. Therefore, fishermen all over the world use this method to preserve fish.

In ancient China, salted fish was called "abalone", and there was an idiom "home of abalone" (this is not the abalone that is now regarded as precious seafood). Guangdong salted fish is famous for its Ma You. It is a kind of salted fish with a strong and special smell. Guangdong specialty salted fish and chicken fried rice is made with this.

2065438+0710127 October, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization was preliminarily sorted out for reference, and China salted fish was in the list of carcinogens.

Second, ways to reduce the harm of salted fish:

1, chemical method

The chemical methods to reduce nitrite mainly include: blocking the synthesis of nitrosamines by adding natural substances, such as garlic juice, ginger juice and aloe juice; Adding bacteriostatic agent can partially replace nitrite, such as ascorbic acid and citric acid, and its mechanism is also to block the combination of nitrite and secondary amine and prevent the formation of nitrosamine; Add some substances, such as monascus pigment, ascorbic acid, etc. , can play a similar role in color development or anticorrosion of nitrite.

2. Biological methods

Biological method mainly uses microorganisms to reduce the pH value in pickled products, produces nitrite-degrading microorganisms in nitrite reductase or directly uses nitrite reductase to reduce the nitrite content in pickled products. Some scholars used Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococcus lactis and Lactobacillus brevis to make direct-cast starter, and the degradation rate of nitrite in sauerkraut reached 98%. This technology can be used in industrial production.

There are also studies on the separation and purification of nitrite reductase from Bacillus megaterium. The optimum temperature and pH of the enzyme reaction are 40℃ and 6.5, and it has good thermal stability. After standing at 80℃ for 4 hours, the enzyme activity is still 70%~80%. Adding compound enzyme preparation composed of this enzyme and specific coenzyme in the curing process of meat can reduce the nitrite residue by 70% without changing the processing conditions of cooked sausages.

References:

Baidu encyclopedia salted fish