Loss of functional properties of proteins during frozen storage and improvement of gel-forming properties of surimi

Surimi is stabilized myofibrillar proteins that have been blended with cryoprotectant for a longer frozen storage life. The functional properties of the myofibrillar proteins are protected during frozen storage when a cryoprotectant was added. Some commonly used cryoprotectants are sorbitol, sucrose, polydextrose, lactitol, litesse, maltodextrin, trehalose, sodium lactate and mixtures of the above cryoprotectants. Phosphate is normally added to surimi in combination with cryoprotectants to reduce viscosity, increase moisture retention and the protein’s ability to reabsorb liquid when the surimi is thawed or tempered, and increase the pH slightly, which leads to improved gel-forming ability, gel strength and cohesiveness. Some food additives also can be used to improve the physical properties of, and prevent the textural degradation of, surimi gels such as egg whites, beef plasma protein (BPP) and whey protein concentrate (WPC). A new surimi-developing process using an acid and alkaline washing method has shown significant potential for use in increasing the concentration of myofibrillar protein in the surimi.