WHEY PROTEINS-HYDROXYPROPYLMETHYLCELLULOSE SYSTEMS: GELATION AND MICROSTRUCTURE

JARA, FEDERICO; PÉREZ, OSCAR E; PILOSOF, ANA MR.

Ambato, Ecuador

Congreso; CIBIA VI. VI Congreso Iberoamericano de Ingeniería de Alimentos; 2007

Universidad Técnica de Ambato

The influence of a commercial type of a low viscosity hydroxypropylmethycellulose (i.e. E50LV) on whey proteins (WPC) gelling properties was studied under thermodynamic compatibility (12 % WPC + 0.25% E50LV, wt) and incompatibility (12 % WPC + 4% E50LV, wt) conditions at neutral pH and room temperature. The binodal curve characterizing phase separation was determined.The micrographs of the non-segregated mixed systems showed a regular pattern of microdomains of proteins imbibed into E50LV matrix. Segregated mixture displayed great zones of protein with irregular edges immersed in a continuous phase of E50LV.Gelation dynamics of segregated mixture showed highly synergistic phenomenon in the solid character (G´) during heating. In the case of non-segregated mixtures, the gelation temperature, the relative viscoelasticity, and G´ of constituted gels, determined by dynamic rheometry, were similar to the  protein.In general terms, the rheological behaviour of these mixed systems were dictated by the biopolymer constituting the continuous phase in segregate mixture or the protein in non-segregated mixture.