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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722

vol. 19, nr. 2 (2005)

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Wheat flour flowability as affected by water activity, storage time and consolidation
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E. Domian, K. Poszytek
Department of Food Engineering and Process Management, Warsaw Agricultural University, Nowoursynowska 159c 02-787 Warszawa, Poland

vol. 19 (2005), nr. 2, pp. 119-124
abstract The influence of water activity, storage time and consolidation on the flowability of wheat flour were evaluated. Powder flowability was measured using a Jenike shear tester according to the Jenike procedure at four levels of normal consolidating stress within the range of 4.9-17.5 kPa. Flour was placed in a humidity chamber to obtain samples of flour at 0.33 and 0.8 water activity. Instantaneous shear tests were performed at temperature of 20°C on each sample, from which the instantaneous flow functions were obtained. Time consolidation tests on the flour at 0.33 and 0.8 water activity were carried out using a Jenike shear cell and consolidating bench for the consolidation time of 1 and 7 days. Temporal flow functions of the flour were determined to quantify the combined effect of moisture content, time and compression stress.
keywords flow function, powder, shear test, wheat flour