The present invention relates to the discovery that specific human taste receptors in the T2R taste receptor family respond to particular bitter compounds present in, e.g., coffee. Also, the invention relates to the discovery of specific compounds and compositions containing that function as bitter taste blockers and the use thereof as bitter taste blockers or flavor modulators in, e.g., coffee and coffee flavored foods, beverages and medicaments. Also, the present invention relates to the discovery of a compound that antagonizes numerous different human T2Rs and the use thereof in assays and as a bitter taste blocker in compositions for ingestion by humans and animals.