The dynamic (oscillatory) rheological properties of imitation pizza cheese containing modified potato starch as a partial caseinate substitute

Imitation pizza cheese provides a useful model system to examine starch–casein interactions from a rheological perspective. Increasing starch content may be a practical and cost-effective means to control the functional properties of imitation pizza cheese. Imitation cheeses containing 2, 3 and 5% (w/w) modified potato starch as a partial caseinate substitute were manufactured and dynamic rheology of these products were compared to a control (0% w/w starch) in temperature sweep analysis. The dynamic rheological properties of caseinate-based imitation cheeses containing various concentrations of modified potato starch were investigated using a strain-controlled rheometer. The storage modulus (G’), the loss modulus (G”) and the loss angle (Tan‌δ) were measured as a function of temperature (35–100°C). The storage modulus and loss modulus of imitation cheeses was significantly increased (P≤0.05) at all examined temperatures (35–100‌℃) with the inclusion of modified potato starch. Inclusion of starch significantly reduced imitation cheese peak Tan‌δ values compared to control (P≤0.05), and the inclusion of 5% (w/w) starch as a partial caseinate substitute had the greatest effect. In sensory evaluation, in terms of texture and mouthfeel, the highest score belonged to control, while in all of samples lowest score observed in sample containing 5% w/w starch. The results of this study showed that varying the level of modified potato starch altered dynamic rheological properties as a function of temperature and thus the functionality (for example, meltability), as well as sensory attributes of imitation pizza cheeses.