Changes in textural and rheological properties of gels from tilapia muscle proteins induced by high pressure and setting

Tilapia meat pastes were prepared with a combination of hydrostatic pressure (200 MPa) and setting (50 degrees C) treatments, to investigate the changes in their theological properties, gel-forming ability, whiteness and protein solubility of their gels. The control, a cooked gel (90 degrees C/30 min), was elastic and white, with low gel-forming ability. Gels formed by setting were elastic, rigid and mainly consisted of covalent bonds. Gels formed by pressurisation were soft and consisted of hydrogen bonds and hydrophobic interactions. Pressurisation prior to setting reinforced the gel structures, by formation of both covalent and non-covalent bonds. Setting prior to pressurisation did not alter the characteristics of the gel. Setting under pressurisation constructed a viscous gel with non-covalent bonds. Various fish gel products were formed in this study. (C) 2006 Elsevier Ltd. All rights reserved.