Enhancement of the Gelling Properties of Sardine Surimi with Transglutaminase and Optimization of its Activity Using Response Surface Methodology

Abstract

In order to improve the gelling properties of sardine surimi gel and to determine the maximum activity range of microbial transglutaminase (MTGase), we investigated the characteristics of surimi gel as a function of MTGase concentration, as well as temperature and reaction time, using the response surface methodology. Specifically, we assessed the following mechanical and physicochemical characteristics of the gel: rheological properties, disulphide bond and total sulfhydryl group content, and waterholding capacity. Our results demonstrated that temperature and enzyme concentration had more influence than reaction time on all dependent variables, incorporation of MTGase markedly ameliorated all the responses. The optimal properties were predicted to be obtained by employing the optimised setting conditions as follows: a concentration of MTGase of 10 g/kg of surimi at 45°C for 1 h. All the mathematical models derived for the various responses were found to be a good fit to predict the data.