In order for fish to keep the nutritious values it undergoes a process called glazing. Glaze is a thin layer of ice appearing on a frozen product surface by spraying it with water aerosol. Such an ice layer prevents the fish from its colour change and losing the meat tissue firmness. Glazing is especially important in case of fat fish storage- here it makes a barrier for oxygen and prevents the fish from rotting. Usually the glaze content equals to 10% of product weight- such glaze is good for 4-month frozen fish storage at the temperature of -20 degrees.
Unfortunately in trade you can often find fish that contain 20 or even 30% of glaze. That is incompliant with technology and trade good practices. Only Abramczyk fish contain minimum glaze which guarantees keeping the highest quality of fish fillets.