The Origin of Unpleasant Aftertastes in Synthetic Sweeteners: A Hypothesis

Computational simulations on the taste mechanism of steviol glycosides based on their interactions with receptor proteins

Steviol glycoside (SG) is a potential natural sugar substitute. The taste of various SG structures differ significantly, while their mechanism has not been thoroughly investigated. To investigate the taste mechanism, molecular docking simulations of SGs with sweet taste receptor TAS1R2 and bitter taste receptor TAS2R4 were conducted. The result suggested that four flexible coils (regions) in TAS1R2 constructed a geometry open pocket in space responsible for the binding of sweeteners. Amino acids that form hydrogen bonds with sweeteners are located in different receptor regions. In bitterness simulation, fewer hydrogen bonds were formed with the increased size of SG molecules. Particularly, there was no interaction between RM and TAS2R4 due to its size, which explains the non-bitterness of RM. Molecular dynamics simulations further indicated that the number of hydrogen bonds between SGs and TAS1R2 was maintained during a simulation time of 50 ns, while sucrose was gradually released from the binding site, leading to the break of interaction. Conclusively, the high sweetness intensity of SG can be attributed to its durative concurrent interaction with the receptor's binding site, and such behavior was determined by the structure feature of SG.

Structure-dependent effects of sweet and sweet taste affecting compounds on their sensorial properties

A reduction in sugar consumption is desirable from a health point of view. However, the sensory profiles of alternative sweet tasting compounds differ from sucrose regarding their temporal profile and undesired side tastes, reducing consumers' acceptance. The present study describes a sensory characterization of a variety of sweet and sweet taste affecting compounds followed by a comparison of similarity to sucrose and a multivariate regression analysis to investigate structural determinants and possible interactions for the temporal profile of the sweetness and side-tastes. The results of the present study suggest a pivotal role for the number of ketones, aromatic rings, double bonds and the M LogP in the temporal profile of sweet and sweet taste affecting compounds. Furthermore, interactions between aggregated physicochemical descriptors demonstrate the complexity of the sensory response, which should be considered in future models to predict a comprehensive sensory profile of sweet and sweet taste affecting compounds.