THE INFLUENCE OF DOUGH MIXING TIME ON WHEAT PROTEIN COMPOSITION AND GLUTEN QUALITY FOR FOUR COMMERCIAL FLOUR MIXTURES

摘要

The effect of mixing time on wheat protein composition and gluten formation wasstudied for three commercial flour mixtures (biscuit, standard and strong) and onedurum flour. Ultracentrifugation was used to separate the fresh, wet gluten from thewheat-flour dough immediately after mixing. Small deformation dynamic rheologicalmeasurements and RP- and SE-HPLC were used to determine the characteristics of thenetwork formed, and the protein composition, respectively. The gluten water content increased due to overmixing for most of the flours. However, no effect of mixing was observed for the storage modulus (G') of gluten for any of the flours. The value of G' of gluten was around 3, 3, 4 and 8 for Standard, Biscuit, Strong and Durum flour, respectively. Therefore, the increased water contentduring prolonged mixing was not related to the effect on G'. The strong flour resultedin the lowest G' for dough, a high G' for gluten and no increase in gluten water contentwith overmixing. The weaker standard flour resulted in the highest gluten water content,which increased considerably with mixing time. The durum flour did not show glutendevelopment and breakdown similar to the other flours. The differences in large UPP,total UPP and large UMP between gluten from the different flours and mixing timesoriginated from the genetic composition of flour proteins.