Rheological properties of HPMC enhanced Surimi analyzed by small- and large-strain tests: I. The effect of concentration and temperature on HPMC flow properties

The authors used a thermal scanning rheological monitor (TSRM) and rotational viscometer to conduct small- and large-strain tests, respectively, in an investigation of the rheological properties of hydroxylpropylmethylcellulose (HPMC) during the annealing process. In the large-strain test, the apparent viscosity of low concentration HPMC (2% and 5%) decreased during heating and then increased during cooling, while that of high concentration HPMC (10%, 15% and 20%) increased during heating and then decreased during cooling. HPMC in 2% concentration behaved as a dilatant fluid. Gels containing 5% and 10% HPMC demonstrated pseudoplastic fluid properties, while gels containing 15% and 20% HPMC concentration demonstrated Bingham-pseudoplastic fluid properties. In the small-strain test at 25 °C, the 2% HPMC sol behaved as a pseudoplastic fluid, while all other sols behaved as a Bingham-pseudoplastic fluid. While reversible thermal gelation and shear thinning properties were observed in HPMC, small- and large-strain tests returned different values for these properties in tests on low concentration HPMC gels. In general, the small-strain test exhibited higher sensitivity and representativity than the large-strain test in HPMC flow properties analysis.