1. What does “adding medicine” mean?
“Adding Medicine ” of shrimp refers to the addition of sodium metabisulfite during transportation. After catching shrimp in the sea, if you don’t pay attention to preservation, it will quickly brown and soften the body, especially the head of the shrimp, which is prone to decay and turning black, affecting sales. This is because shrimp usually die quickly after fishing, and enzymes in the shrimp begin to react and contaminate a large number of microorganisms. To ensure fishing efficiency, fishermen often go out to sea for a long time, and every year, some of the shrimp caught in the sea will spoil and rot due to not being kept fresh in time. Due to the low price and convenient use of sodium metabisulfite (commonly known as shrimp medicine or shrimp powder), fishermen often use it for preservation. It is precisely because of it that mainland cities can also enjoy delicious seafood.
2. Characteristics of sodium metabisulfite
Sodium metabisulfite is a recommended preservative for aquatic products by the United Nations, as well as a preservative for shellfish aquatic products, including shrimp, recommended by the Codex Alimentarius Commission (CAC). The National Food Safety Standard of the People’s Republic of China for Food Additives (GB 1896.7-2015) and the National Food Safety Standard of the People’s Republic of China for the Use of Food Additives (GB 2760-2014) make provisions for preservatives and antioxidants, sodium metabisulfite. The maximum usage of sodium metabisulfite in fresh aquatic products (limited to shrimp and crab products only) and frozen aquatic products and their products is 0.1 g · kg-1 (100 mg · kg-1). It is safe to use this drug within a limited concentration.
3. Will the excessive use of sodium metabisulfite cause harm?
Although sodium metabisulfite can prevent shrimp from turning black, it produces water-soluble sulfur dioxide during the decomposition process and adheres to shrimp. Sulfur dioxide (SO2) is a colorless gas that is soluble in water and has toxic effects on the human respiratory system and conjunctiva; It can inhibit, destroy or activate the activity of certain enzymes, disrupt the metabolism of sugars and proteins, and thus affect the growth and development of the body. Therefore, if sodium metabisulfite is used in excess, there still exists a certain level of toxicity.
4. Current usage status of sodium metabisulfite
Previously, some fishermen lacked food safety awareness and would use excessive amounts of sodium metabisulfite for preservation. In recent years, with the increasing awareness of safety among fishermen, the standardization of using sodium metabisulfite has been strengthened, and the phenomenon of sulfur dioxide exceeding the standard in marine shrimp and crabs has rapidly decreased.