The determination of moisture in wheat and flour: A study of “moisture testing” in water ovens and electric ovens

Abstract

The nature of the problem of moisture determinations on materials such as flour and wheat is discussed shortly. It is not possible to obtain by over drying true values for moisture contents. What is sought is a convenient and reliable procedure giving strictly reproducible figures possessing full comparative value. This was the object of the work described, the main lines of which should be applicable to agricultural products of many kinds.The electrically heated air oven is the most convenient and suitable instrument for routine purposes, and comparative results show that it allows of far more reliable work than the water oven.Determinations of apparent moisture content have been made on a sample of wheat flour in electric ovens at temperatures ranging from 90° to 140° C. and for periods of heating ranging from 1 to 14 hours, the technique and number of determinations (about 400 altogether) being such that the results were suitable for statistical examination. The probable errors of single determinations were calculated for several sets of results and did not exceed 0·05 per cent. The results given show that at several temperatures, variation in time of heating over a considerable range does not affect the values obtained. In the light of these results it was possible to assess the reliability, as well as the convenience, of various possible procedures.