Starch Measurement with the Brabender® Viscograph Family
All over the world, the Viscograph is the standard instrument for measuring the viscosity of starch and starch containing products as a function of temperature and time.
Viscograph tests fully comply with international standards:
• ICC standard no. 169
• AACC standard no. 61-01
The Viscograph truly measures native starches - wheat, corn, potato, rice starch - just like all types of modified starches like food and industrial starches the rheological properties of which have been modified according to the specific application.
Its versatility has made the Viscograph the most commonly used instrument of its kind all over the world.
The Viscograph family comprises:
• Viscograph-E
• Micro Visco-Amylo-Graph®
Specification | ||
| Viscograph-E | Micro Visco-Amylo-Graph® |
Sample volume | approx. 450 ml | approx. 100 ml |
Heating power | 550 W | 500 W |
Speed | 0-200 U/min | 0-300 U/min |
PC connection | USB | USB |
Mains | 115/230 V, 50/60 Hz | 115/230 V, 50/60 Hz |
Dimensions (H x W x D) | 900 x 550 x 400 mm | 750 x 500 x 380 mm |
Heating / Cooling rate | 0.5 - 3.0°C / min | 1.5 - 10°C / min |
Measuring principle
The sample - a starch-water suspension - is heated up within a rotating bowl and cooled down again, both under controlled conditions. Apart from a simple heating - holding - cooling cycle, complex temperature programs can be run.
A measuring sensor reaching into the sample is deflected according to the viscosity of the sample in the bowl. This deflection is measured as torque - mechanically against a spring in the Viscograph Pt 100, or electronically with the Viscograph E and Micro Visco-Amylo-Graph®.
Using the Viscograph, you will get a complete profile of the rheological properties of your starch or starch containing products.
The Viscogram
The resulting Viscogram supplies reproducible data about the rheological properties of the starch tested - thick or thin boiling, different thickening capacities, gelification, high or low hot viscosity, different cold viscosity, stability, etc. - with food starch such as thickening agents or binders for sauces or pudding as well as with industrial starch (e.g. wall paper adhesive) for the paper and textile industries. The torque curve supplies the following relevant data
• beginning of gelatinization
• gelatinization maximum and temperature
• viscosity during holding
• viscosity at the end of cooling
32-bit Windows software
Extensive, comfortable 32-bit Windows software is available for running the tests, data recording, and automatic evaluation of the results. The data are stored in MS Access database format and can easily be imported into other applications.
A powerful correlation program allows a direct comparison of up to 15 tests with each other and enables quick assessment of trends or irregularities in data.
A new Universal Evaluation program was created as an additional software package for Viscograph evaluation. With this software, the user has several formulas at hand for defining evaluations of his own, e.g. evaluation of maxima within a certain time range, search for the first time when a predefined viscosity is reached in the test, evaluation every 5 minutes or every 3°C temperature increase, etc.
