The invention provides a tobacco composition for use in a smoking article or a smokeless tobacco composition that includes an additive derived from a flower of the Nicotiana species. The additive can be a flower isolate derived from a flower of the Nicotiana species. In certain embodiments, the flower isolate is in the form of an extract from a flower of the Nicotiana species or in the form of a chemically transformed flower isolate, the chemical transformation being selected from acid/base reaction, hydrolysis, thermal treatment, and enzymatic treatment, the chemical transformation releasing at least a portion of a glycosidically bound compound in the flower of the Nicotiana species. The invention also provides smoking articles and smokeless tobacco compositions that include the flower additives described herein, and methods for preparing an additive derived from a flower of the Nicotiana species for addition to a tobacco composition.