Saturated and unsaturated compounds having sweet, salt or umami taste enhancement qualities. The compounds have the structure: where R1═H or methyl; R2 is selected from the group consisting of H, C1-C4 alkyl, alkenyl and methylene; R3 is selected from the group consisting of H, C1-C8 straight or branched chain alkyl, alkenyl, dienalkyl or phenyl; or if R1═H, R2 and R3 taken together can represent cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, or cyclohexenyl; R4 is selected from the group consisting of H, methyl and ethyl; R5 is selected from the group consisting of H, methyl and ethyl; R6 is selected from the group consisting of H, C1-C9 straight or branched chain alkyl, alkenyl, alkyldienyl, acyclic or containing no more than one ring; with the proviso that in structure 1 when R4 is H or Me; and R5═H or methyl, R6 may be selected from the group described above or phenyl.