Inibidores de proteases na qualidade do gel de surimi de sub-produtos do processamento de pescada-foguete (Macrodon ancylodon)

Abstract

The quality of the surimi gel depends on the integrity of the myofibril protein structure. The structure could be lost during the heating process by a denaturation phenomenon, which is caused by neutral and heat stable proteases and consequently forming a pour gel. The objective of the work was to control the denaturation intensity using BSA and egg white as a protease inhibitors, under different processing conditions, in gels of King weakfish ( Macrodon ancylodon ) surimi . The analysis of gel strength, that involve tests of firmness, compressibility and cohesiveness by instrumental methods, and the myofibril fragmentation index (MFI) and SDS-PAGE electrophoresis were used for evaluating the inhibitors performance in different treatments: 5 formulations, including the use of salts (NaCl, NH4Cl) and 3 heating conditions for kamaboko gel formation. Results indicate that all gels with inhibitors presented significantly (P<0,05) more gel strength

than the control. The bigger intensity of protein band, in the electrophoresis SDS-PAGE in the gels studied with humidity between 72 and 74%, low MFI (<21) and salt concentration of 2,7%, was demonstrated that the inhibitor BSA was better than the egg white. No remarkable proteolitic activity was observed in the surimi gel control (without inhibitors). However, it is possible to be noted an intensity of myosin electrophoresis band, when the inhibitors are used, mainly BSA, that acts in protecting protein structure, increasing gel strength.