Effect of precooking temperature and microbial transglutaminase on the gelling properties of blue crab (Callinectes sapidus) proteins

Crustacean proteins denature and aggregate at similar temperature than other muscle proteins. However, crustacean proteins are able to gel even after being cooked. The mechanism associated to this behaviour remains unclear and differs from the gelling mechanism of muscle proteins from most of the animals. The objective of this work was to determine the effect of cooking temperature on the gelling properties of blue crab ( Callinectes sapidus) muscle proteins. Live crabs were precooked at 50, 60, 70, and 120°C for 30min. Precooked crabmeat was homogenized in a cutter with no added salt and mixed with 0 (control) or 6g/kg of microbial transglutaminase (MTGase). The mixture was stuffed in steel tubes and settled at 40°C for 30min before cooking at 90°C for 15min (control was cooked directly at 90°C). Changes on the mechanical properties (TPA), colour attributes and water holding capacity (WHC) were evaluated. Gels from crabmeat precooked at 120°C showed better mechanical properties than gels obtained at 50, 60, or 70°C. MTGase improved the mechanical properties of gels in both cooking treatments: setting and direct cooking. Results suggest that crab proteins are able to gel after a complete denaturation/aggregation process and they can interact with MTGase.