Determination of Moisture in Cereals: Review of Methods in Common Use

Abstract

Physical methods for moisture determination include oven drying at a specified temperature, with or without application of reduced pressure and use of desiccants, and direct reading after distillation with an immiscible solvent; methods depending on electrical conductivity or capacitance are limited in their accuracy by that of the reference method used for standardization. Of chemical methods, modifications of the Karl Fischer technique (using iodine, sulphur dioxide, pyridine and methanol) have found greatest acceptance. A survey of all these methods indicates that, whilst each may give results consistent with itself, the results of different methods do not necessarily agree. Accordingly, the need is indicated for further fundamental investigation of the nature of the problems involved in moisture assessment.