Interaction Between Nanocellulose And Myofibrillar Protein And Its Effect On Gelation Properties

Nanocellulose(NC),a novel renewable organic nanomaterial,has attracted much more attention in food industry due to outstanding rheological properties thus serving as the agents of thickening,stabilizing,and modifying texture.In this article,we prepared carboxymethylated cellulose nanofibril(c CNF)with different degree of substitution and nanocellulose(NC)with different morphology,and investigated the effects of surface charge and morphology(L/D)of NC on the physical properties of beef myofibril protein gel involving water-holding capacity,microstructure,rheological properties,and textural properties,aiming to provide the theoretical foundation and technical support in the development of restructured meat products.First,we prepared c CNF with different degree of substitutions via the combination method of monochloroacetic acid modification,hydrochloric acid hydrolysis,and mechanical treatment,and characterized their physicochemical properties,as well as further investigated the effects of the difference in their surface charge on the beef myofibril protein gelation properties.In brief,we successfully prepared three carboxymethylated cellulose nanofibrils with different substitution degrees(i.e.,0,0.36,0.72 mmol/g),and added them to MP.The composite gels were prepared by heating and characterized.The results showed that some hydroxyl groups on the cellulose chain were replaced by carboxymethyl,and the stability of the suspension increased with the increase of the degree of substitution.The addition of c CNF significantly improved the water holding capacity,network structure and gel strength of MP,and increased with the increase of packing concentration.However,there is strong electrostatic repulsion inside the gel filled with high degree of substitution c CNF,which is not conducive to the construction and stability of the gel network.Next,we prepared three different NC with different morphology(L/D)including cellulose nanofibrils(CNF),cellulose nanosphere(CNS),and cellulose nanocrystals(CNC),and characterized them via physicochemical properties.Moreover,we prepared composite protein gels using above three NCs with different concentration gradient(0.1,0.3,0.5,1,1.5,2 wt%),and studied their effects on the gel properties.The results showed that the diameters of CNF,CNS,and CNC were 35,30,18 nm,respectively and the ζ-potential of NC showed no significant difference.The addition of three NCs could significantly lower the water-loss of protein gel after heating treatment,and the incorporation of NCs strengthen the viscoelasticity of composite protein gel,and accelerated the phase transition(sol to gel)during heating processing.Due to the larger aspect ratio,CNF is more prone to physical entanglement and penetration,so it can significantly improve the gel properties of MP at lower filling concentration.As described above,NC can be deemed to be a functional food ingredient to improve the organoleptic quality of meat products.More importantly,the corresponding processing properties of different NCs were controlled via various preparation methods to meet the different demands of reconstructed meat products.