Saliva pH Affects the Sweetness Sense

Abstract Objectives The aim of this study was to establish a prediction system for taste sense according to the biochemical data of saliva. Research Methods & Procedures A total of 100 participants aged 20 years or older without physical, mental, and dental disability were included in the study. Saliva samples were collected from the participants and subjected to biochemical analyses. Taste examination (sweetness, saltiness, sourness, and bitterness) was performed using the dropped disc method. Correlation analysis and multiple regression analysis were performed between the taste sense properties and biochemical data of saliva. Results Multiple regression analysis showed that sweetness sensitivity (in which a higher score indicates lower sensitivity) was significantly affected by various biochemical properties, with the strongest influence of pH. The following prediction equation was determined: Sweetness sensitivity = 1.38 + (-0.12 × Low pH (1: if pH < 6.7, 0: otherwise)) + (0.80 × High pH (1: if pH > 7.3, 0: otherwise)) + (0.04 × Fe (μg/dL)). Analysis of variance showed an overall significant effect of these variables on sweetness sensitivity (R2＝0.74, P < 0.01). Conclusion Saliva pH most strongly affects the sweetness sensitivity. This prediction can be used for evaluations of variations in dietary choices and help individuals make healthy food choices to maintain health.