Phenolic protein interactions in relation to the gelation properties of canola protein

The influences of sinapic acid and thomasidioic acid on the rheological characteristics of canola protein gels were investigated. Interactions between these phenolic compounds and the canola protein were evaluated using equilibrium dialysis. At pH 4.5, there was binding between sinapic acid and the canola protein through electrostatic interactions, while at pH 7 and 8.5, there appeared to a hydrophobic association between thomasidioic acid and the protein. Based on dynamic rheology, the presence of either compound resulted in deterioration of the characteristics of heat-induced gels for the canola protein. A combination of 2% thomasidioic acid and 0.1 M NaCl at pH 8.5, however, produced a gel whose characteristics were similar to the canola protein dispersed in water. (C) 1997 Published by Elsevier Science Ltd on behalf of the Canadian Institute of Food Science and Technology.