Gelling properties of hake muscle with addition of freeze-thawed and freeze-dried soy phosphatidylcholine liposomes protected with trehalose

Soy phosphatidylcholine liposomes made with addition of trehalose as cryoprotectant were subjected to freeze-thawing and freeze-drying treatments, and subsequently incorporated in salt-ground hake (M. merluccius) muscle to study their effects on protein aggregation, water binding and thermal gelation. Both liposomal preparations presented similar particle size (≈215 nm, expressed as z-average) and strong electronegative zeta potential (−46 mV). The addition of both types of liposomal preparations led to more water trapped within the myofibrillar protein in the salt-ground muscle, as observed by water holding capacity (WHC) and low field nuclear magnetic resonance (LF-NMR). However, the liposomes interfered strongly with the thermal gelation ability of the muscle protein. Differential scanning calorimetry (DSC) analysis of the salt-ground muscle showed that the liposomes caused an increase in the main transition temperature associated with the actin molecule, with a concomitant reduction in total enthalpy change. The hydration state of the trehalose-containing liposomes did not play a significant role in textural properties of the resulting gels. The detrimental role of liposomes in the texture of fish gels should be considered in the design of functional fish products.The authors wish to thank the Spanish Ministry of Economy and Competitiveness (MINECO) for financial support (projects AGL2014-52825 and AGL2017-84161-C2-1-R).Peer reviewe