GRL paste viscosity indicator for rapid determination of alpha-amylase in Canadian Red Spring Wheat

An instrument called the paste viscosity indicator (PVI) has been developed at the Grain Research laboratory (GRL) for measuring the paste viscosity of a heated ground grain-water slurry. Increased resistance offered to the stirring device upon heating a ground grain-water slurry is reflected in a voltage signal representing the current requirements of a small DC motor. Paste viscosity decreases with increasing α-amylase levels in the ground grain. The viscosity is measured by a digital panel meter which retains its reading after a testing period of 3 or 3.5 min. The machine is portable (8.8 kg) and does not require a running water source. Operation is in simple steps and sample containers are low cost and disposable. The method correlates well with Falling Number method over the range of 65 – 425 s for Canadian Western Red Spring wheat. As such, it may be well-suited for implementation into a carlot or cargo monitoring program for assessment of preharvest sprout-damage.Key words: Amylase, wheat, control, sprout-damage