The present invention relates to the discovery that specific human taste receptors in the T2R taste receptor family respond to particular bitter compounds, i.e., chlorogenic lactone compounds that contribute at least partially to the bitter taste of many coffee beverages. The present invention further relates to the use of these receptors in assays for identifying ligands that modulate the activation of these taste receptors by chlorogenic lactones and related compounds and which may be used as additives and/or removed from foods, beverages and medicinals in order to modify (block) T2R-associated bitter taste. A preferred embodiment is the use of the identified compounds as additives in coffee and coffee-flavored foods, beverages and medicinals.