Extensograph
A Extensograph is a laboratory device, with which the elongation properties ( elasticity , plasticity ) of a wheat - dough can be tested practical or durum wheat dough. The elongation properties provide information about the behavior of a dough on the proof . The formation of CO 2 gas causes the dough to expand and gain in volume. In order to maintain the volume, the adhesive must be able to stretch, but it must not collapse immediately afterwards. These dough properties can be read off in the extensogram. In the bakery it is possible to make statements about the glue quality, the gas retention capacity, the fermentation tolerance and the dough flow.
This is why it is used in the laboratories of mills , large bakeries and baking agent manufacturers . The extensograph was developed by Carl Wilhelm Brabender. The devices are sold worldwide by Brabender in Duisburg and CWB in the USA.
Principle of the method
A wheat dough kneaded in the Farinograph with the addition of 2% table salt according to ICC, ISO or AACC standards is formed into a strand of dough. Then it is left to rest in a fermentation chamber at 30 ° C so that the glue can relax. The dough is then stretched with a hook after 45, 90 and 135 minutes until it breaks and the force required for this is recorded in the form of a curve (extensogram). The curve can be used to determine the stretchability, stretch resistance, a ratio and the fermentation tolerance of a dough. The extensogram is therefore an important and practical dough rheological analysis method for assessing wheat dough worldwide. The investigation is z. B. carried out according to the ICC standard No. 114/1. Other standards are, for example, ISO or AACC standards. While older devices still recorded a curve on recording paper, today a connected computer with special software is used for evaluation. The curves generated in the respective dough rings provide information about the gluten extensibility after these times.
application
Since an extensogram provides important information about the plastic and elastic properties of dough, predictions can be made about the behavior of the dough in the bakery. So z. B. can be determined whether the dough is more suitable for rolls, toasted bread or hard biscuits. The extensogram is also well suited to test the effect and dosage of flour treatment agents or baking agents ( ascorbic acid , cystine , cysteine , proteinases ), as the curves show this very clearly.
Relationship between extensogram shape and pastry properties:
Evaluation of an extensogram
Bun flour
Toast flour
Hard biscuit flour
Individual evidence
- ↑ Wilfried Seibel (Ed.): Warenkunde grain . AgriMedia, Bergen / Dumme 2005, ISBN 3-86037-257-2 .
- ↑ Extensograph-E - Investigate rheological dough properties. Brabender, accessed July 12, 2017 .
- ↑ Extensograph®-E. CWB Brabender, accessed on July 12, 2017 .
- ^ Method for using the Brabender Extensograph. (No longer available online.) ICC , 1992, archived from the original on May 13, 2013 ; accessed on July 12, 2017 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Extensograph®-E. (PDF; 502 kB) Product brochure. Brabender, accessed July 12, 2017 .
- ^ Burghard Kirsch: Milling technology, materials science. Composition, study, evaluation and use of grain and grain products . 8th edition. Bayerischer Müllerbund, Munich 2016, ISBN 978-3-9812436-6-6 .
