Production of low-salt restructured fish products from Mexican flounder (Cyclopsetta chittendeni) using microbial transglutaminase or whey protein concentrate as binders

Mexican flounder (Cyclopsetta chittendenni) is an abundant fish specie usually caught as shrimp by-catch in the north of the Gulf of Mexico, but due to its small size is mostly discarded after dying during catching and handling operations. The objective of this work was to determine the feasibility of obtaining low-salt restructured fish products using flounder flesh as raw material. Two levels of salt (10 and 20 g/kg) were tested and microbial transglutaminasa (MTGase) (3 g/kg) or whey protein concentrate (WPC) (10 g/kg) were used as binders. Changes in mechanical properties (texture profile analysis and puncture test), expressible water and colour attributes were measured. Good gels from Mexican flounder were obtained at both salt levels. The use of MTGase improved the mechanical properties at both salt levels. However, WPC improved the mechanical properties of gels obtained only with 20 g salt/kg. The restructured fish products showed a light greyish colour adequate for commercialization.