MERCAPTOETHANOL, N-ETHYLMALEIMIDE, PROPYLENE-GLYCOL AND UREA EFFECTS ON RHEOLOGICAL PROPERTIES OF THERMALLY INDUCED BETA-LACTOGLOBULIN GELS AT ALKALINE PH

In the absence of added NaCl, electrostatic repulsion prevented thermal gelation of beta-lactoglobulin, pH 8.0, but added propylene glycol or urea supported weak gel structure formation. When the electrostatic barrier was reduced by added NaCl, gelation occurred and gel strength was enhanced by propylene glycol addition and reduced by added urea, N-ethylmaleimide or merceptoethanol. Cohesiveness of beta-lactoglobulin gels containing NaCl decreased on adding propylene glycol, mercaptoethanol or N-ethylmaleimide but increased on adding urea. Relative to cohesiveness, elasticity/springiness was higher following N-ethylamleimide or mercaptoethanol addition but lower following urea addition. Molecular forces involved in gel structure formation and maintenance were proposed based on observed effects.