Water holding capacity of sodium-reduced chicken breast myofibrillar protein gel as affected by combined CaCl2 and high-pressure processing

Summary The water holding capacity (WHC) of sodium-reduced (0.3 m sodium chloride, corresponding to the salt percentage (w/v) of 1.755%) myofibrillar protein (MP) gel in response to combined calcium chloride (CaCl 2 , 20, 60, 100 m m ) and high-pressure processing (HPP, 200 MPa, 10 min) was investigated. The results showed that 200 MPa + 20 m m CaCl 2 synergistically increased the WHC of MP gel via reducing particle size of MP solutions, strengthening hydrogen-bonding and disulphide-bonding, promoting formation of β-sheet and uncoiling of α-helix, exposing tryptophan residues, enhancing hydrophobic interactions of aliphatic residues and forming a compact and continuous networked gel structure. However, high concentrations (≥60 m m ) of CaCl 2 could attenuate the enhancing effects of HPP on the WHC by inducing decreased hydrogen bonds, fewer tryptophan residues exposed and coarser and aggregated gel structures with large cavities. Therefore, a combined moderate HPP and low concentration of CaCl 2 is a potential alternative for developing sodium-reduced meat products.