EFFECT OF STORAGE TIME ON FALLING NUMBER AND APPARENT VISCOSITY OF WHEAT FLOUR GRUELS

The objective of the research study was to determine the effect of storage time on changes in the falling number and apparent viscosity of wheat flour gruels. The flour was obtained by milling wheat in a laboratory whereas the wheat used was grown using two different levels of agrotechnology: basic (A1) and advanced (A2 - increased nitrogen fertilizing, advanced chemical protection). In particular, the research conducted aimed at the determination of the correlation between the falling number and apparent viscosity. The rheological properties of water slurries were measured using a spindle-type rotational rheometer with coaxial cylinders i.e. a MettlerRheomat RM 180 model. It was proved that the maximum and final viscosity changed during storage, and the direction and intensity of the transformation depended on the type of flour. During storage, an increase was confirmed in the falling number and a decrease in apparent viscosity of gruels made of wheat flour types obtained by milling the grain produced using the basic level of agrotechnology (A1). The flour types obtained by milling grain produced using the advanced level of agrotechnology were characterized by a more stable rheological properties during storage. A significant linear correlation (Pearson's correlation, p < 0.05) was found between the maximum and final viscosity of wheat gruels and the value of falling number.