Creating novel food textures: Modifying rheology of starch granule suspensions by cold-set whey protein gelation

•Heat-denatured whey proteins in starch suspensions gelled by calcium addition.•Viscous or paste-like materials were formed after cold-set gelation.•Swollen starch granules modified the structure and rheology of these systems.•These materials may be useful for reduced calorie food products.

There is increasing interest in creating novel structures in food products so as to create desirable textural characteristics. Cold-set gelation of pre-heated (90 °C/10 min) whey protein isolate (WPI) solutions (2.5, 5.0 and 10.0 g/100 g) and WPI-starch mixtures (2.5 g/100 g and 3.75 g/100 g, respectively) were initiated with calcium chloride (10 and 20 mmol/L). Calcium addition promoted gelation of the pre-heated systems at ambient temperature and led to increased turbidity, complex shear modulus (G*), and optical lightness. These measured properties increased with increasing protein and/or calcium concentration, which was attributed to more extensive protein network formation. In the WPI-starch mixed systems, the presence of swollen starch granules caused discontinuous protein network formation and led to lower gelation kinetics in comparison to protein-only WPI gels. Our results have useful implications for the formulation of semi-solid food products with specific rheological properties, i.e., gel-like or paste-like characteristics.