Imitation crab, also known as surimi, is a processed food designed to mimic the flavor and texture of real crab meat. Often found in sushi rolls and seafood salads, its “imitation” status causes confusion for individuals with shellfish allergies. Because allergic reactions can be severe, consumers must carefully examine its composition and manufacturing process.
What Is Imitation Crab Made Of?
The primary component of imitation crab is surimi, a highly processed fish paste that accounts for 35% to 50% of the final product. Surimi is made from the muscle tissue of white-fleshed fin fish, most commonly Alaska Pollock, Hake, or Cod. The fish is deboned, washed, and minced into a bland paste.
Manufacturers blend surimi with non-fish ingredients to achieve the desired texture, color, and stability. Common additives include water, starches (such as wheat, potato, or corn) for binding, and egg whites for protein. Sugars and vegetable oils are also introduced to stabilize the product and enhance texture. The final mixture is heated, pressed into crab-like shapes, and given its signature red-orange coloring.
The Allergy Risk from Fin Fish
Since the core ingredient of surimi is fin fish, imitation crab presents a direct allergy risk to individuals with a fin fish allergy. This is a distinct concern from a shellfish allergy, as they contain different allergenic proteins. The major allergen in fin fish is parvalbumin, a highly heat-stable protein found in muscle tissue.
The main allergen in crustacean shellfish, such as crab or shrimp, is tropomyosin. While a shellfish allergy does not automatically mean a fin fish allergy exists, those with both conditions must strictly avoid imitation crab due to its fin fish base.
Navigating Shellfish Contamination and Labeling
The main risk for individuals with a crustacean shellfish allergy stems from cross-contamination or the inclusion of shellfish-derived flavorings. To enhance the “crab” taste, some manufacturers include small amounts of actual crab or other shellfish extracts. Even minimal amounts, often less than 2% of the total product, can contain enough protein to trigger a severe reaction.
A second risk is allergen cross-contact, which occurs when imitation crab is processed on shared equipment or in the same facility as real crustaceans like crab or shrimp. Trace amounts of shellfish proteins can transfer during manufacturing, creating an undeclared hazard. Therefore, the product cannot be considered safe without careful investigation.
The Food Allergen Labeling and Consumer Protection Act (FALCPA) requires packaged foods to declare major food allergens, including “Fish” and “Crustacean Shellfish.” When crustacean shellfish is an ingredient, the label must specify the exact species, such as “crab” or “shrimp.” Fin fish must also be identified by species, such as “Pollock.”
FALCPA does not require manufacturers to use “may contain” statements for potential cross-contact, though some companies do so. A lack of a warning does not guarantee the product was made on dedicated equipment. For maximum safety, individuals with severe allergies should seek products that confirm dedicated processing lines or contact the manufacturer directly.