Effects of sucrose on salivary flow and composition: differences between real and sham intake

Human saliva contains numerous salivary components that are fundamental for a healthy oral environment and the oral processing of foods. To study a possible differential influence of orosensory stimulation and metabolic activation on salivary composition, human parotid salivary flow, pH, A(280), and alpha-amylase activity were measured before, during and after real or sham (sip-and-spit) sucrose intakes. Variations in these salivary characteristics were related to perceived satiety. Sucrose, as either real or sham intake, increased salivary flow and pH and decreased A(280) before returning to pre-intake levels. Increased salivation was dependent on the sucrose concentration and was accompanied with a higher pH and lower A(280). After sucrose ingestion, the salivary alpha-amylase activity increased, while no increase occurred after sham sucrose intake. Similarly, rated satiety increased with real but not by sham sucrose intake. This indicated that salivary alpha-amylase is associated with perceived satiety controlled by caloric perception downstream of the oral cavity.