Gel Formation of Fish Structural Proteins Under Mild Acidic Conditions: Comparison With Conventional Surimi Gelation and Applications

Abstract

Washed fish meat homogenate in water could be converted into a gel by lowering its pH using weak organic acids such as acetic or lactic acid. Gelation results in imbibing of significant amount of water in the gel matrix of the proteins. The gel could be suitably diluted to get dispersions in which the fish structural proteins are highly soluble. Mild heating of the dispersion results in reduction of viscosity and its conversion into a free-flowing solution. Solubility of the proteins in the dispersion is not affected by temperatures as high as 100°C and/or high-speed centrifugation. However, the proteins are precipitated if traces of salt are added to the heated dispersions. The acid-induced gelation could be used to develop surimi-type restructured products from shark meat. Gel dispersions from shark and other fish species could be spray dried into protein powders. The dispersions can also be used as edible coatings to prevent quality loss in fishery products during chilled or frozen storage.