Comparative moisture determinations in dried vegetables by drying after lyophilisation or by the Karl Fischer method

Abstract

Moisture determinations in dried vegetables were made after lyophilisation by drying in a vacuum desiccator at 70°, 60° and 50° and room temperature. The findings of Makower & Nielsen could not be corroborated, but it is considered that the results at 50° are a close approach to the moisture content. Since these results are in good agreement with the values found by titration with Karl Fischer reagent after extraction with formamide, the titration method may be accepted as a standard procedure for the determination of moisture in dried vegetables. Determination of the end‐point of drying under vacuum at 70° after lyophilisation of the material appears to be impossible, probably because of thermal decomposition soon after drying starts, probably within 3 h.