169 Method for using the Brabender Viscograph

Methods Type: Generic Methods
Key data
Number: 169
Analyte: Brabender Viscograph
Matrix: Starch, Modified Starch and Starch Derivatives, Grain, Legume and Tuber Starches
Year of Approval: 2000
Scope: This standard specifies a method, using the Brabender Viscograph, for the determination of the gelatinization and retrogradation properties of starch, indicated by the viscosity of a starch-water suspension during heating and cooling.

This method is applicable to starch, modified starch and starch derivatives.
This method is applicable for grain, legume, and tuber starches.

Principle: A starch-water suspension is heated at a constant rate of increase and decrease, resp., of temperature in a bowl rotating at a specified constant rotational speed. During heating and cooling, the viscosity of the sample is recorded continuously.

The test involves a temperature program designed to show and characterise the viscosity behaviour of starch as influenced by increasing and decreasing temperatures and by mechanical stirring. The viscosity of starch pastes measured at different stages during their preparation is a guide to their pasting behaviour.

References

  • ICC-Standard No. 130, Sampling of milling products (semolina, flours, agglomerated flours, and by-products; 1980
  • ICC-Standard No.110/1, Determination of the moisture content of cereals and cereal products (Practical method); 1976
  • ISO 3696, Water for analytical laboratory use - Specification and test methods; 1987

Definitions

The Viscograph viscosity is the resistance, measured as torque and expressed in arbitrary units (Brabender Units, BU), of a starch-water suspension heated in the Brabender Viscograph at a constant rate of increase (heating) and decrease (cooling) of temperature and with the bowl rotating at a specified constant rotational speed.
The ”hot-paste” Viscograph viscosity is the viscosity reached under the conditions of the method just before the paste is being cooled.
The ”cold-paste” Viscograph viscosity is the viscosity reached under the conditions of the method after cooling the paste to the final temperature (50°C).