Effect of NaCl on processing properties of pork myofibrillar protein emulsion

The objective of this study was to evaluate the effect of NaCl concentration on rheological properties and water holding capacity of myofibrillar protein emulsion. Myofibrillar proteins were extracted from pork and NaCl was added at 0. 2,0. 4 and 0. 6 mol·L-1followed by mixing. Rheological properties,water mobility,distribution characteristics and microstructure of the mixture were analyzed.The results showed that 0. 6 mol·L-1NaCl myofibrillar protein and its emulsion had the greatest storage modulus( G') and loss modulus( G″),but G' and G″ changed little at 0.2 mol·L-1NaCl and the stable gel network structure was not formed. Compared to the mixture at 0. 4 and 0. 6 mol·L-1NaCl,the T21 and T22of myofibrillar protein emulsion and its gel decreased greatly,and its peak area decreased as well,while peak area of T23 increased at 0. 2 mol·L-1NaCl. The myofibrillar proteins and its emulsion gel at 0. 6 mol·L-1NaCl had orderly,uniform and compact three-dimensional network,and the interface of protein membrane was smooth and complete,whereas the heat induced gel at 0. 2 mol·L-1NaCl had a lot of flake protein and big pore,and the interface of protein membrane was ruptured,and as a result,gel structure was unstable. Conclusions: The ability to form emulsion gel became stronger with NaCl concentration increasing. At low salt,the water mobility decreased and the immobilized water went out to be free moisture,resulting in a serious juice loss and the decrease of water-holding capacity.