Molecular Taste: Molecular Approaches to Understand Food Polyphenols Astringency and Bitterness

Dr. Susana Soares, from Faculdade de Ciências da Universidade do Porto (FCUP), Portugal, will join us this year to present a talk entitled “Molecular Taste: Molecular Approaches to Understand Food Polyphenols Astringency and Bitterness".

As per Dr. Soares, phenolic compounds (PC) are linked to astringency sensation and bitter taste. Regarding astringency, studies typically use simple models, with pure PC and/or proteins, far from what is likely to occur in the oral cavity. Different oral models have been developed in our last works, comprising different oral epithelia (buccal mucosa (TR146) and tongue (HSC-3)) and other main oral constituents (human saliva and mucosal pellicle). These models have been used to study the interaction with more or less complex PC extracts as well as with food matrices, such as coffee. The studied extracts were rich in different families of (food) PC, namely flavanols (a green tea extract), anthocyanins (a red wine extract), gallotannins (a tannic acid extract), and flavonols (an onion extract). It was observed a different interaction for the different families of PC and also that the several oral constituents have different implications. Moreover, some of these studies aligned the in vitro models with sensory studies data. Overall, the results seem to point out that the different oral constituents can have different functions in astringency perception as well as being involved in different phases of astringency perception. These differences can be related to the perception of different astringency sub-qualities.

Regarding bitterness, Dr. Soares and her team have used a cell-based assay to screen which human bitter taste receptors are activated by a library of PC from different families. The bitter taste receptors (TAS2Rs) activated by these polyphenols and the half-maximum effective concentration (EC₅₀) of each agonist-TAS2Rs pair were determined. TAS2R5 seems to be the only receptor somehow “specifically” activated by natural (condensed) tannins, while TAS2R7 seems more tuned for hydrolysable (ellagi)tannins. Additionally, at the concentrations usually found for these compounds in foodstuffs, they can actively contribute to bitter taste, especially ETs. Ultimately, it seems that when considering the bitterness of polyphenols, bitterness and astringency sensory properties seem to be undeniably linked, especially to explain and compare in vitro and in vivo inconsistencies.

Join us in Polyphenols Applications 2022 and benefit from the experience of professional researchers like Dr. Soares.

Polyphenols Applications 2022 Congress
September 28-30, 2022 - Valencia, Spain
www.polyphenols-site.com