The retention of l*C-labelled ethyl acetate, n-propanol and acetone in freeze-dried food gels is studied. Fractional retention of the initially present volatiles increases with increasing solids concentration and decreases with increasing initial volatile content. Retention also decreases with increasing sample thickness in fast-frozen samples, and is lower in rapidly frozen than in slowly frozen samples.Humidification causes release of retained volatiles, the new level of retention depending upon relative humidity. The results indicate that the predominant retention mechanism is entrapment in microregions, with a small contribution due to adsorption.