The role of saliva in oral processing: Reconsidering the breakdown path paradigm

We discuss food oral processing research over the last two decades and consider strategies for quantifying the food breakdown model, originally conceptualized by Hutchings and Lillford. The key innovation in their seminal 1988 paper was shifting the focus from intact food properties, measured in the lab, toward strategies to capture the dynamic nature of eating. This has stimulated great progress in the field, but a key aspect missing in oral processing research is the conversion of the Hutchings and Lillford breakdown path conceptual model into quantifiable parameters considered in the context of physiological factors such as saliva and oral movements. To address these shortcomings, we propose the following analysis: Hutchings's and Lillford's definitions of "Structure" and "Lubrication" are incomplete and they comprise many and varied physicochemical properties. We offer, here, a deeper analysis of each parameter, and propose strategies for researchers to consider in their quantification as an update of the Hutchings and Lillford Breakdown path.