Studies on the secondary structure and heat-induced gelation of pork myofibrillar proteins as affected by pH.

【Objective】 The objective is to study the effect of pH on the secondary structure,α-helix of pork myofibrillar protein,and the hardness,water holding capacity (WHC) and microstructure of its heat-induced gel. 【Method】 The α-helix of pork myofibrillar protein under different pH were measured by circular dichroism (CD),and the hardness,WHC and microstructure of the heat-induced gel were determined by texture analyzer,centrifugation method and scanning electron microscope (SEM),respectively. 【Result】 The α-helix of pork myofibrillar protein and WHC of its heat-induced gel increased with pH away from pI,the hardness reached its maximum when pH was 6.0,the gel had a uniform and orderly microstructure in neutral,while it had disorderly and uneven microstructure with polymer in the acidic. 【Conclusion】 The α-helix of myofibrillar protein is positive correlated with the WHC of its heat-induced gelation,and the gel has an orderly microstructure with more α-helix,while rough microstructure with less α-helix.