RHEOLOGICAL STUDY ON GELATION OF SOYBEAN-11S PROTEIN BY GLUCONO-DELTA-LACTONE

Dynamic viscoelasticity studies on gelation of soybean 11S protein by glucono-delta-lactone have been done to analyze the gelation process of tofu. Observed gelation curves at constant temperatures were well approximated by first-order reaction kinetics. The saturated storage modulus depended mainly on the concentration of 11S protein. The saturated modulus was proportional to 3.4th power of 11S concentrations. The rate constant of the gelation increased with increasing gelling temperature and was mainly governed by the concentration of glucono-delta-lactone. The activation energy of the gelation was calculated to be 1.5 x 10(1) kJ/mol from an Arrhenius plot of the rate constants. The latent time at which the shear modulus began to deviate from the baseline became shorter with increasing concentration of glucono-delta-lactone. However, the latent time was not shortened by an increase in protein concentration, in contrast to previous findings for many other protein gels.