Production of novel pasta filata analogs containing pea protein isolate using a direct steam injection cooker stretcher: Changes in microstructure and texture

Stretched curd has a very characteristic structure, and unique melting and stretching properties. This research explored how the addition of pea protein isolate (PPI) may modify the microstructure and rheological properties of a stretched curd made with rennet-casein. Model cheese analogs were obtained by hydrating protein powders together with palm oil and pre-gelatinized maize starch, using different PPI/casein ratios The structure was formed using a direct steam injection cooker-stretcher. Differences in microstructure were observed using confocal microscopy and X-ray tomography, and rheological properties were evaluated using small and large amplitude oscillatory rheology. Cheese containing PPI had a higher elastic modulus compared to the rennet-casein control, a more brittle structure, and showed a change in melting behavior. Addition of 30 % of PPI already showed differences in the lipid droplet distribution, while still maintaining an anisotropic structure. At 50/50 PPI-casein protein ratios the structure was instead that typical of emulsion filled gels. This study demonstrates how by replacing rennet casein with PPI it is possible to modulate the structural features of cheese analogs.