Does bolus structure influence the fate of volatile compounds and nutrients throughout mastication and dynamic digestion in vitro? Case study on a model cheese and its vegetal analogue

In the context of sustainable development of agriculture towards improved environment and nutrition, a dietary transition including more plant-based food products is desirable. Yet, this transition is currently slowed by technological, sensorial, or nutritional challenges. To help the design of acceptable plant-based foods, interdisciplinary research projects are required. In this article, we present an integrated approach to study semi-solid plant-based foods from production to in vitro digestion, including the effect of in vitro mastication on volatile compound release as a sensory indicator and on nutrient hydrolysis as a nutrition indicator. To do so, a cow’s milk cheese and its vegetal soy-based analogue with matched biochemical composition and texture were developed. A human mastication study was conducted to characterize bolus formation, saliva incorporation, and bolus fragmentation. The results were used to optimize the parameters of a mastication simulator to obtain artificial boluses with similar characteristics as those produced in vivo . To test the effect of bolus particle size distribution, the release of volatile compounds from in vitro masticated boluses was compared to that from boluses produced by strong grinding. Boluses were also subjected to dynamic in vitro gastrointestinal digestion to study the fate of various nutrients including lipid, protein, and vitamin E. Both the food type and the bolus fragmentation degree influenced the results, volatile compound release behavior also depending on the partition coefficient, and gastric digestion kinetics being systematically slower for lipid and protein from strongly ground boluses, attributed to amplified destabilization phenomena of the protein network.