Oral processing and dynamics of texture perception in commercial gluten-free breads

There is an increasing demand for gluten-free products, with the texture being a critical aspect. The aim of this work was to study the food bolus properties of gluten-free breads in relation to the dynamics of sensations perceived during its consumption. In this study, five-commercial gluten-free breads and two regular breads were analysed for their texture, crumb structure, and moisture content. Bread bolus particle size after three chews, bolus characteristics at the swallowing point, and oral activity were determined. The dynamics of textural sensations during bread consumption was evaluated using the temporal dominance of sensations (TDS) technique. Texture and structure properties vary among gluten-free breads being some of them close to regular breads (crumb with more and smaller cells that shows low hardness and high springiness) that lead to different in-mouth breakdown and TDS patterns. At the beginning, harder breads with low springiness values resulted in hard dominant sensations, in contrast, breads with low hardness and high springiness values were perceived soft and spongy. Breads that fragmented into a greater number of small size particles created crumbly and sandy sensations, characteristic of gluten-free breads with large air cell sizes. Compact sensation appeared in breads with low saliva uptake during bolus formation, while pasty and sticky sensations were related to a cohesive and adhesive bolus, respectively. Not only structure and mechanical properties, but also its oral behaviour in terms of fragmentation and bolus formation can fully explain the dynamics of texture perception of gluten-free breads.