Flow behavior studies of kefir type systems

Kefir type samples were prepared using two different commercial starter cultures and bovine full fat milk. The milk samples were fermented at either 30 or 35 °C. Separate series of samples to which 1% or 2% or 3% caseinates were added, prepared the same way. All samples were rheologically tested in stirred as well as in set form. Shear viscosity measurements showed that the apparent viscosities exhibited by the kefir samples were starter culture type, fermentation temperature and caseinate content dependent. Similar results were obtained from lubricated squeeze flow viscometry measurements. The experimental data was discussed in the light of possible mechanisms involved in the structure net work formation of the samples during their preparation.