Mixing behaviour of a zero-developed dough compared to a flour-water mixture.

摘要

The Z-blade mixing behaviour of zero-developed (ZD) doughs from the flours of two wheat cultivars of different gluten strength was compared to that of conventionally mixed dough made from the same flours. In farinograph experiments, use of ZD dough led to shorter development time (with less energy requirement), less stability time, and consequently earlier breakdown compared to conventional mixing of the corresponding flour-water mixture. Mixing of ZD doughs led to an almost similar decrease of glutenin macro-polymer (GMP) wet weight as that of doughs prepared from flour-water mixtures. However, comparison of wet weight of re-assembled GMP revealed that until time-to-peak (TTP) mixing, there was no difference in GMP recovery with respect to the starting material used in the z-blade mixing experiments. Beyond TTP, recovery of GMP in doughs prepared from both starting materials was reduced. The results of large-strain deformation rheology showed strong visco-elastic behaviour as characterised by the highest values of fracture properties (except epsilon H), followed by a decline in those properties upon further mixing for doughs mixed from both flour-water mixture and ZD dough from both types of wheat cultivars. It was concluded that at mixing regimes before TTP, there was no difference between ZD doughs and flour-water mixtures in the mixer. When ZD dough is used as a starting material for dough preparation instead of flour, extra care should be taken not to over-mix the developing dough..