The impact of mastication, salivation and food bolus formation on salt release during bread consumption

Abstract

Health authorities recommend higher fibre and lower salt content in bread products. However, these basic ingredients of bread composition are multifunctional, and important changes in their content influence the texture, flavour and acceptability of the product. This study was designed to investigate the link between oral processing, bolus formation and sodium release during the consumption of four different breads that varied in composition and structure. Chewing behaviour was determined by surface electromyography, and salivation was quantified from the water content of the boluses collected. The kinetics of bread degradation during food bolus formation was characterised by measuring the bolus heterogeneity by texture image analysis, and sodium release into the saliva was quantified. Mastication and salivation varied between products and between subjects, thus highlighting different bolus formation strategies. In vivo salt release was mainly explained by mastication parameters. The initial slope of sodium release increased when the chewing muscles' activity increased, and the maximum sodium concentration was reached later when more masticatory cycles were required to reach the swallowing point.

Chewing bread: impact on alpha-amylase secretion and oral digestion

“…Finally, the saliva uptake for a given bread was found to depend on individuals, which demonstrated the inter-individual differences in salivary behaviour, as already reported in a previous study of bread. 16 We also observed changes in salivary composition. Protein content increased significantly throughout the chewing process and depended on the bread.…”

“…In the case of bread, the understanding of food oral processing and bolus formation has been recently studied extensively. 7,[10][11][12][13][14][15][16][17] In particular, the presence of a thick and dry crust on bread (i.e., a French baguette) influences the chewing force, chewing duration, salivary uptake and bolus particle size and hardness compared to crumbs alone. 10,11 Wheat breads with higher density were found to require longer mastication times than wheat bread with a lower density.…”

Physics of food structure breakdown and bolus formation during oral processing of hard and soft solids

“…This is highlighted particularly strongly by Tournier et al [44], who found significant inter-individual differences in the amount of saliva taken up by the bolus following mastication of bread. Mastication (number of chews) and salivation may adapt to the differences in composition and structure of the bread, although in this study it is difficult to distinguish the contributions from bread hardness, moisture content, taste and other parameters.…”

“…A key observation from the recent literature is that the middle stages of oral processing is still not well understood beyond observations of agglomeration, moisture increases and a sensation of dryness/hydration [41*, 44,46]. In the later periods of oral processing, bolus rheology is considered important, but inter-individual differences make it challenging to quantify how it influences sensory perception.…”

Oral health–related food selectivity among French independently living elders

“…First, no oral significant factor of dislike‐related selectivity score was revealed. This was quite surprising because we thought that the pleasure encountered, while eating would be influenced by the number of contacts existing between posterior teeth, which may be either the consequence of impaired taste sensitivity secondary to dental deafferentation or decreased flavour release from bolus fragmentation with reduced number of occluding teeth . Then, oral discomfort–related food selective behaviour was found to be closely dependent on oral health–related quality of life and occlusal status.…”