The Effect of Experimental Salivary Flow Reduction on the Masticatory Process and the Physical Properties of the Food Bolus

Abstract

Saliva plays an important role in bolus formation. But the actual influence of the reduction in salivary flow on bolus formation during mastication has not been fully elucidated. Thus, the aim of the present study is to investigate the effect of salivary flow reduction on the process of mastication and food bolus formation in adults. Twenty adults were recruited as the subjects. Fishsausage and bread were used as sample foods. For eachsubject the food bolus just before swallowing was collected and measured according to texture profile analysis. The timing of the measurement was 40~80 minutes after oral administration of 1.0 g of atropine sulfate, when the salivary flow decreased to half the normal condition. Before administration of atropine sulfate, the same measurement was performed and the data was used as control. The number of chewing strokes and chewing time before swallowing for eachtest food under the atropine sulfate administration was significantly larger than that of the control. The changes in bolus properties for eachtest food under administration of atropine sulfate were similar to those in the normal condition. Some differences were recognized in the cohesiveness of the bread bolus, but there was no significant difference in hardness and adhesiveness of food bolus for eachsample between before and after administration of atropine sulfate. It was suggested that the chewing time is prolonged to form the food bolus suitable for swallowing when salivary flow is reduced.