The increased interest in novel food technologies using mild treatments, nowdays are very much in demand. Although the effect of high pressure on the food systems was reported over 100 years ago, it is only in recent years that this process has been seriously considered as a viable method for food processing and preservation. It was shown that high pressure processing has a significant influence on the protein conformation as well as on their interactions with other food components. The aim of this work was to investigate the rheological properties as well as the phase transition temperatures of model suspension prepared by mixing of high pressured beta-lactoglobulin and carboxymethylcellulose (CMC). Treatment of beta-lactoglobulin suspensions (10% w/w)was carried out in the semi-industrial equioment for high pressurization using pressure of 300, 400, 500 and 600 MPa for 5 and 10 minutes. The influence of CMC addition on flowing behavious and phase transition temperatures of beta-lactoglobulin was investigated using rotational rheometar set at 20 0C and by using equipment for differential thermal analysis (DTA), respectively. The results obtained have shown that investigated beta-lactoglobulin model systems were non-Newtonian fluid that exhibit dilatant properties. CMC addition caused a significant (P<0.05) decrease of apparent viscosity related to the intensity of applied pressure and duration of pressure treatment, indicating incompatibility between biopolymers. It was evident that CMC in model systems act as cryoprotectant with significant (P<0.05) effect on freezing and thawing temperatures depression, respectively. These changes in phase-transition temperatures giv rise to potential commercial application of these model systems because of reduced ice-crystal damage during freezing and thawing.

Food processing technology