| Abstract: | ![]()
Possible Standardization of Viscosity Measuring Procedures for a Comparative Valuation of the Rheological Properties and Behaviour of Starches . As generally known, in both starch research and starch industries numerous different apparatus for viscosity measurement are used which produce rheological data by the scale and measuring systems of the instruments applied. However, the test-data obtained can not be compared on principle because of those different scale and measuring systems fixed to each instrument. Furthermore, no suitable procedure as standardized method is availably up to now. The standardization of suitable methods on the other side presupposes that the apparatus for viscosity measurement themselves produce reproducible results when uniform working directions are used. For that reason the viscosities of various potato, maize, rice and wheat starches were determined under different test conditions by utilizing the Brabender viscograph, Rotovisco instrument and Hoeppler falling-ball viscosimeter in order to establish optimum conditions for the reproducibility of results obtained. Thereby those three apparatus for viscosity measurement were selected in particular under technological aspects of application. As result of the comprehensive investigations it seems to be quite possible to criticize and review comparatively the rheological properties and the rheological behaviour of starches with regard to their importance in the special field of technical application, if the existance of suitable and also standardized methods guarantees a sufficient reproducibility of the test-data. |
