Described are mixtures of at least four of the alkadienamides defined according to the structure: ##STR00001## wherein R represents C.sub.1-C.sub.2 n-alkyl; R.sub.1 is 2-methyl-1-propyl and R.sub.2 is hydrogen, or R.sub.1 and R.sub.2 taken together is a moiety having the formula ##STR00002## wherein n is 4 or 5, or compositions containing substantial concentrations of such mixtures, prepared according to novel processes: (a) extraction of a ground substantially dried fruit of one of the Piper species, Piper longum Linn or Piper peepuloides; (b) natural product-forming synthesis; or (c) synthetic product-forming synthesis. Also described are uses of the thus-formed products for augmenting, enhancing or imparting an aroma, taste, chemesthetic effect and/or antibacterial effect in or to a consumable material and/or in the oral cavity and/or on the mammalian epidermis.