Relations between rheological properties, saliva-induced structure breakdown and sensory texture attributes of custards

The relevance of initial rheological properties and mechanical and enzymatic structure breakdown in determining selected sensory texture attributes of custards was studied. The so-called structure breakdown cell was used to characterize saliva-induced breakdown, i.e., by monitoring digestion of starch by amylase from saliva. Based on rheological parameters, some attributes could be predicted well, while others more poorly or were not predicted. Predictable attributes were primarily determined by bulk properties; poorly and nonpredictable attributes originated from properties of the outer low-viscosity surface layers or were not related to rheological properties. Both mechanical and enzymatic breakdown were important for creaminess, thickness and melting. Enzymatic breakdown was the dominant mechanism involved in the perception of fattiness, roughness and stickiness but not heterogeneity. Creaminess was the only attribute that was also determined by initial rheological properties and mechanical and enzymatic breakdown. Custards displaying high creaminess ratings had high initial stiffness, the structure broke down at low stress and enzymatic breakdown was slow. Microstructural organization of starch plays a dominating role in defining rheological and breakdown behavior of custards and in this way determines creaminess to a high extent.