Olfactory, gas chromatographic and mass-spectral analyses of fecal volatiles traced to ingested licorice and apple.

Volatile components of two foodstuffs with characteristic aromas, apple and licorice, and fecal samples obtained from subjects on high-apple and licorice diets, were analyzed by head-space gas chromatography and gas chromatography-mass spectrometer. The volatile compounds characteristic of the odors of apple and licorice were detected by "sniffing" the GC effluent. The aromatic component of licorice was identified by GC-MS as anethole [1-methoxy-4-(2-propenyl) benzene]. The aromatic component of apple could not be chemically characterized by our GC-MS system even though readily detected by the nose. Head-space, GC-MS analysis of fecal volatiles offers a means of tracing odorous and non-odorous components to ingested foodstuffs with potential applications to clinical and forensic medicine and anthropology.