Effects of microbial transglutaminase (MTGase) on functional and rheological properties of big head (Hypophtalmichthys nobilis) fish skin gelatin

The aims of this study was improve the rheological charactristics of gelatin obtained from the skin of the Big head by rheological test. In this study gelatin was extracted from big head (Hypophtalmichthys nobilis) fish skin and the effect of microbial transglutaminase (MTGase) on gelatin in different concentrations (1, 3 and 6 u/g gelatin) and reaction times (15, 30 and 60 minutes) was examined. The result showed that addition of MTGase in minimum concentration and reaction time ( 1u/g gelatin in 15 minute reaction time) increase the gel strength from 228±1g to 250g significantly (p≤0.01) whitout the changing the color of result gelatin. Furthermore, increasing concentrations of MTGase redused the gel strength of gelatin. Also the addition of MTGase increased the viscosity in all shear rates and improved melting and gelling point. The increase in storage modulus (G') values with the addition of MTGase indicated the formation of firmer gels and also changes in G' and G" values during the heating and cooling sweep test showed increase in melting point and gelling point. It is conclude that the application of 1-6 U/g of MTase can improve the quality of driven gelatin from big head fish.