Rheological investigations of alkaline-induced gelation of skimmed milk and reconstituted skimmed milk concentrates

The gelation of milk and of reconstituted milk at various concentrations of solids, as induced by alkaline pH, has been investigated using dynamic rhe ological methods. The gels formed at pH 12 were relatively weak and exhibit ed an exponential relationship between the elastic modulus G' and the prote in concentration phi (G' similar to phi(3.9)). Gelation time decreased with both increasing temperature and protein-concentration. Chromatographic ana lysis of the proteins showed that storage at pH 12 resulted in changes in t heir chemical structure. (C) 2000 Elsevier Science Ltd. All rights reserved .