Relationships between the response of the sweet taste receptor, salivation toward sweeteners, and sweetness intensity

Sweeteners are widely used in food products, and their sweetness potency is usually evaluated by comparing it with that of sucrose. This, however, has led to confusion as some sweeteners are evaluated based on their maximum value of sweet taste response, while others are evaluated by their threshold value. Here, we aimed to develop a novel nonverbal sweetness evaluation system through the sweet taste signal transduction by comparing the responses of the sweet taste receptor, salivation, taste intensity, and preference among six sweeteners. The hT1r2/hT1r3 sweet taste receptor responses represented the input signal of the sweet taste signal transduction, while salivation, sweet taste intensity, and participants' preferences represented the output signals by the gustatory–salivary reflex, primary gustatory cortex area, and the secondary gustatory cortex, respectively. Our results showed that the sweet taste receptor, sweet intensity, and salivary secretion responses were concentration‐dependent and expressed exponentially. Moreover, the results comparing coefficients showed 15–35 times more sensitivity between the response of hT1r2/hT1r3 and the salivation or the sweet taste intensity in non‐nutrient sweeteners. The preference graph curve was not exponential, suggesting that the sweetener preference was not related to the sweet taste receptor, salivation, or sweet taste intensity. These results may suggest that the sweet taste signal of the non‐nutritive sweeteners might be maintained by taste reception by hT1r2/hT1r3 to taste recognition in the primary gustatory area and that receptor responses and salivation could be used as indicators of sweetness intensity. Sweet intensity, and salivary secretion responses were concentration‐dependent. Sensitivity differences between taste receptor and intensity ranged from 15 to 35. Sweeteners preference is not correlated with the sweet taste receptor.