Quality Characteristics of High Pressure-Induced Hake (Merluccius capensis) Protein Gels with and without MTGase

Abstract

The effects of microbial transglutaminase (MTGase; 0.5%, w/w) and high hydrostatic pressure (HHP) on the quality of protein gels from unwashed mince of hake (Merluccius capensis) trimmings were studied. MTGase incorporation improved texture. Protein solubility was lower for those gels containing MTGase, as a result of myosin heavy chain cross-linking. HHP improved texture. Pressure level was the most important HHP parameter, since higher levels (300 vs. 100 MPa) augmented gel strength (GS). A positive synergistic effect of MTGase and HHP was found for some properties, such as GS, yielding improved gels from a raw material that otherwise shows poor gelation.

Keywords:

• hydrostatic pressure
• microbial transglutaminase
• hake
• physicochemical properties
• electrophoresis

This research was funded by QCA III MARE-FEDER Project 22-05-01-FDR-00006. Author Carlos L. Cardoso thanks Fundação para a Ciência e Tecnologia for the PhD grant (SFRH/BD/36455/2007). Furthermore, the authors would like to thank Cátia Silva, Dipl. Eng., for providing MTGase; and Sofia Palma, MSc and Teresa Moita, PhD (INRB, I.P./L-IPIMAR) for their invaluable help with scanning electron microscopy (SEM).