“Cooking” with Acid

When we say a food is cooked, we normally mean the food’s texture has been changed by the application of heat. Heat acts to tighten a protein food’s fibers and make the food firmer. The heat’s action also affects the color of the food, gradually changing it from slightly translucent to opaque, and, when red pigments are present, gradually destroying them.

The application of acid has a similar effect on delicate seafood. When tender-textured seafood comes into contact with highly acidic liquids such as citrus juice or vinegar, the liquid quickly penetrates its soft, porous muscle tissue. The acid then changes the protein structure of the seafood’s flesh. The seafood acquires a cooked flavor and appearance even though it has not been heated.