Sweet taste perception is mediated by a single heterodimeric receptor composed of two distinct subunits, called TAS1R2 and TAS1R3 belonging to the class C G protein-coupled receptors (GPCRs). Like other class C GPCRs, TAS1R2 and TAS1R3 subunits share a large N-terminal domain (NTD) linked to the heptahelical transmembrane domain by a short cysteine-rich region. This unique receptor recognizes a wide variety of sweet tasting compounds including natural sugars, synthetic and natural sweeteners. The existence of multiple ligand binding sites on the TAS1R2/TAS1R3 receptor explains the phenomenon of synergy observed between some combinations of sweeteners. The blending of sweeteners is widely used in food products and beverages. For instance, mixtures of saccharin and cyclamate or sucralose and acesulfame-K help to increase sweetness and allow bitter taste reduction. Here, we used functional expression of the human sweet taste receptor using heterologous HEK293 cells and calcium mobilization assays to investigate sweet taste synergism between binary mixtures of 6 sweeteners varying in chemical structure and type, including neotame, rebaudioside A, rebaudioside M, mogroside V, allulose and the plant sweet-tasting protein, thaumatin. We demonstrated that EC50 values measured for sweeteners alone are correlated to their sweetness potency. Cellular assays revealed that some of the tested binary mixtures were synergistic. These results revealed the usefulness of performing in vitro cellular assay prior to laborious sensory analysis to help to find new solutions for sugar-reduced formulations.

This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 774293