People enjoy eating fish as a healthier alternative to poultry or red meat products. Salmon fillets, shelled shrimp, mahi mahi steaks, or catfish strips are commonly sold in frozen form. The individually packed nature of these products, especially in regards to fillets, makes cooking and preparation very easy. The reality is that there may be more in fish, and other frozen meat products, than you realize. The worst part is that labeling of one specific, potentially toxic ingredient is not mandatory in the United States.
Sodium tripolyphosphate (STTP) is an inorganic compound that is a common additive to detergents, industrial products, and even food products. It’s a colorless salt that is a common food preservative, making seafood, meats, and poultry appear firm, glossy, and plump. Some seafood retailers may even soak wild-caught fish in a quick chemical bath with STTP to achieve the aforementioned effects.
What Is STTP?
STTP contains three phosphate units that are linked together. In brief, it undergoes a couple stages of manufacturing. STTP is a commercial emulsifier that results from the neutralization of phosphoric acid with sodium hydroxide. The mixture that you get from that process is monosodium phosphate and disodium phosphate. Manufacturers then heat that mixture to 500-550º C to achieve food-grade STTP.
Why Is STTP Added To Food?
Ultimately, STTP helps food absorb water, making the food more appealing to the consumer. This affects the original weight of the meat or seafood product you purchase, as food products absorb more water after soaking in an STTP bath. You can often tell if fish has been soaked in an STTP solution because a milky white liquid will ooze out as it cooks. You may also notice that the fish reduces in size during the cooking process.
The color, odor, and texture of seafood are three primary concerns to manufacturers, especially before freezing. Without an STTP bath, the fish may smell more and thaw with a darker appearance. For this reason, the U.S. Food and Drug Administration (USFDA) has authorized the use of STTP. Otherwise, fish that was freshly cut may experience damage by ice crystals and protein denaturation during the freezing process.
STTP is also added to meat to improve the texture and color. It interacts with the inherent amino acids or hydroxyl groups in proteins, improving water retention of the protein product.
Is It Safe?
The USFDA considers STTP to be generally recognized as safe (GRAS). Because STTP is associated with this label, there is no suggested dosage. It’s also exempted from the typical Federal Food, Drug, and Cosmetic Act (FFDCA) for food additive tolerance requirements. Additionally, food manufacturers don’t have to include it as an ingredient on labels. In large quantities, however, STTP is not safe. In fact, STTP is a suspected neurotoxin, carcinogen and a registered pesticide and air contaminant in the state of California. Because of CA Prop. 65, any food containing STTP must list it as an ingredient. According to several reports, STTP can cause skin and eye irritation, in addition to digestive and respiratory troubles. Keep all of this in mind when you purchase fish, meat, or poultry, especially in pre-packaged frozen varieties.
Can You Steer Clear Of STTP?
Yes, it is possible if you do your due diligence by asking questions. If you live outside of California, keep in mind that frozen varieties don’t have to list it as an ingredient. It’s better to buy fresh and develop a rapport with your local butcher. Ask if the meat or seafood has been packaged or treated with STTP. It’s quite common in scallops and shrimp, so keep this information in mind the next time you purchase meat or seafood.
