Effect of pH on the Dynamic Rheological Properties of Chicken Breast Salt-Soluble Proteins During Heat-Induced Gelation

The effects of pH (4.5, 5.5, 6.5, and 7.5) on the nondestructive dynamic rheological properties of chicken breast salt-soluble proteins were investigated during heating in .6 M NaCl. No major rheological transitions occurred during heating at 1 C/min for proteins at pH 4.5, whereas several transition peaks were observed at pH 5.5, 6.5, and 7.5. The first transition temperature for loss modulus occurred before that for storage modulus under all conditions, indicating that proteins unfolded prior to aggregating into a gel matrix. Proteins at pH 5.5 exhibited lower thermal stability than proteins at pH 6.5 and 7.5 The first transition peak of storage modulus became broader as pH decreased from 7.5 to 5.5. Salt soluble proteins at pH 4.5 exhibited more viscous properties and did not form a gel network. Gels at pH 6.5 and 7.5 were more elastic.