Modifying sensory perception of chocolate coated rice waffles through bite-to-bite contrast: an application case study using 3D inkjet printing.

Consumers expect perceptual constancy between multiple bites of the same food. In this study, we investigated how sweetness, creaminess, expected fullness and liking of chocolate coated rice waffles can be modified by bite-to-bite variation in chocolate thickness. 3D inkjet printing was used to accurately deposit the chocolate layers varying in thickness (0.8, 1.6 and 3.2 mm) onto rice waffles. In the first study, single bites of rice waffles with a homogeneous chocolate coating were evaluated. With increasing thickness of chocolate coating, the sweetness, creaminess, and expected fullness increased significantly. In the second study, we evaluated seven chocolate coated rice waffles containing a constant total chocolate amount but different chocolate thicknesses between three sequential bites. The order of chocolate thickness between bites had significant, but small effects on sweetness, expected fullness and liking. Interestingly, rice waffles with a homogeneous chocolate coating were preferred over rice waffles with an inhomogeneous chocolate coating. Neither recency nor primacy effects were sufficient to explain sweetness perception in this study. We conclude that the sweetness of chocolate coated rice waffles can be modified by bite-to-bite variation in chocolate thickness. This study demonstrates that 3D inkjet printing allows the production of foods with bite-to-bite contrast, which possibly might be used for healthier food product design.