Protein aggregation, water binding and thermal gelation of salt-ground hake muscle in the presence of wet and dried soy phosphatidylcholine liposomes

Abstract

Different soy phosphatidylcholine liposomal preparations (fresh, high-pressure-treated, frozen-thawed, freeze-dried and spray-dried) were incorporated in salt-ground hake (M. merluccius) muscle and their effects on protein aggregation, water binding and thermal gelation were studied. Hydrodynamic properties of liposomes varied within the range of 123–507 nm for particle size and −40 to −49.5 mV for zeta potential. Addition of liposomes to the salt-ground muscle decreased protein solubility and increased water holding capacity, regardless of the vesicle particle size or membrane surface charge. Liposomes caused an increase in protein thermal stability, as observed by DSC, and also increased the spacing between myofibrils, leading to more water trapped within the myofibrillar protein network, as revealed by the LF-NMR-1H study. The presence of liposomes slightly modified the viscoelastic behaviour and interfered with the thermal aggregation of muscle proteins, the mechanisms for this interference being different depending on the type of liposome preparation (wet or dry form). The present work suggests the possible use of a highly appreciated fish species, which could be subjected to landing obligation under Total Allowable Catch regulations (EU), for the development of a high-added-value fish product functionalized by the addition of liposomes.