Studies on fish and pork paste gelation by dynamic rheology and circular dichroism

The muscle paste of fish, pork, and their mixtures were prepared to study the gelling characteristics by dynamic reheological measurement. The gelation mechanisms of muscle paste were also investigated by circular dichroism. Gel formation of fish paste occurred in 2 steps of 5 to the alpha-helix unfolding of myosin, which responded the melting temperatures of 40 and 50 degrees C for fish myosin and 50 and 60 degrees C for pork myosin, respectively. Alpha-helix unfolding of myosin was beneficial for gel formation. During gel formation, G' of muscle paste was linearly related to alpha-helical content of myosin. The interactions of fish and pork proteins at high temperature (> 35 degrees C) could change the gel forming characteristics of muscle paste. Mixed paste exhibited a similar gelation pattern to individual fish paste with 2 visible increases in G'. Addition of pork could suppress the breakdown of fish gell structure at approximately 50 degrees C. Mixing pork and silver carp in certain could improve the gel properties of silver carp porducts.