RHEOLOGY OF BUILDUP, BREAKDOWN, AND REBODYING OF ACID CASEIN GELS

Dynamic oscillations were measured during in situ buildup and breakdow n of acid casein gels induced by glucono-delta-lactone at varying temp eratures and skim milk solids concentrations. The gel structure was gr adually broken down by continuous oscillation at high strains. Using h igh strains (up to .8), gel moduli were lowered to a few percentages o f their original value with no wall slip problems. No equilibrium valu es were found for either buildup or breakdown. The time course of buil dup and rebodying was complex, but different gels were affected by she ar in the same way in relation to their initial values. Strain was the main rate determining parameter.