Relationship of the moisture content of Finnish wheat flour and relative humidity

Authors

• Yu-Yen Linko Research and Development Laboratories, Vaasan Höyrymylly Osakeyhtiö, Helsinki, Finland
• Pekka Linko Research and Development Laboratories, Vaasan Höyrymylly Osakeyhtiö, Helsinki, Finland

DOI: https://doi.org/10.23986/afsci.71694

Abstract

Changes in the moisture content of Finnish commercial wheat flour stored at variable relative humidities, representing the conditions typical of flour storage in Finland, were investigated. It could be shown that flour of 15 % moisture at the time of packing tends to dry considerably during normal storage conditions. Owing to the hysteresis effect, the moisture content of once dried flour is not likely to reach detrimental levels during normal storage, even if the relative humidity would exceed the critical level of 75—80 % for short periods. Minimum warehouse relative humidity was observed during Januay, at which time flour moisture had decreased to 6.7 %. The equilibrium humidity for flour of 15 % original moisture content was found to be about 70 %.