THE MICROBIAL CONTENT OF SOFT WHEAT FLOUR'

Numerous investigations have shown the microbial flora of flour to be extremely heterogenous, including molds and yeasts as well as bacteria. The amount of microbial development de-pends upon the moisture content of the flour. Thom and Le-Fevre (1921) showed that a moisture content of less than 13 per cent inhibits growth of all organisms. According to Arnoldow (1908) most bacteria and molds grow in flour when the moisture content is greater than 17 per cent. The bacterial content may reach such enormous numbers as 310,000 to 5,200,000 per gram according to Turley (1922). Kent-Jones and Amos (1930) dem-onstrated that freshly milled patent flour may contain 20,000 or even less organisms per gram, while lower grades may contain 300,000 or less. These investigators found also that storage of flour decreases the microbial content; the rate of decrease depending upon the moisture content and storage temperature. Sometime ago a southern milling company reported difficulty regarding the keeping quality of its flour. Since rancidity de-veloped rapidly, a bacteriological investigation was made, to determine why this particular product lacked the keeping quali-ties of other flours on the market. METHODS OF PROCEDURE Ten-gram samples of wheat and flour, collected from the im-portant milling stages, were thoroughly shaken in liter bottles of sterile water for at least oDe-half hour to insure uniform sus-pensions before making further dilutions and plating. Nutrient 1 Report of an investigation conducted in the laboratories of the Departmen