The volatile content of the effluent from the retronasal aroma simulator (RAS) was compared with that of human breath using mass spectroscopy (MS-Nose). The ratios of volatile compounds from the RAS were closely related to those from the panelists' breath with the correlation coefficients ranging from 0.97 to 0.99 from model food systems. A greater sensitivity using the RAS was achieved because higher concentrations of volatiles in the MS-Nose were produced from the RAS than from the breath. In analyzing the effects on volatility of RAS parameters including airflow rate, temperature, saliva ratio, and blending speed, airflow rate had the greatest effect. The correlation coefficients for the real food systems studied ranged from 0.83 to 0.99. The RAS gives a good approximation of time-averaged flavor release in the mouth as defined by breath-by-breath measurements.