Saliva pH affects the sweetness sense.

OBJECTIVES: The aim of this study was to establish a prediction system for taste sense according to the biochemical data of saliva. METHODS: The present study included 100 participants ages ≥20 y without physical, mental, or dental disabilities. Saliva samples were collected from the participants and subjected to biochemical analyses. Taste examination (sweetness, saltiness, sourness, and bitterness) was performed using the dropped disk method. Correlation analysis and multiple regression analysis were performed between the taste sense properties and biochemical data of saliva. RESULTS: Multiple regression analysis demonstrated that sweetness sensitivity (in which a higher score indicates lower sensitivity) was significantly affected by various biochemical properties, with the strongest influence being 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 to help individuals make healthy food choices to maintain health.