Evaluation of the Degree of Starch Pyrodextrinization Using Binary Digital Image Colorimetry

Pyrodextrins widely used in industry are obtained using thermal destruction of starch in the absence of a catalyst. The viscosity and solubility of pyrodextrins are determined by the degree of pyrodextrinization of starch, which is usually assessed visually by the color intensity of the reaction products. The article summarizes information on the mechanism of starch pyrodextrinization and examines the effect of temperature and heating time on the color intensity of the resulting dextrins. It is proposed to use binary digital image colorimetry to measure the level of dextrin binarization; on the basis of the obtained values, taking into account a number of assumptions, the degree of starch pyrodextrinization is estimated. Using two-factor analysis of variance, the significance of the effect of temperature and heating time on the degree of starch pyrodextrinization α₀ is established. Using multiple regression, an equation for the dependence of α₀ on these parameters is obtained. A diagram of isothermal pyrodextrinization of starch characterizing the conditions for obtaining dextrins with different degrees of pyrodextrinization is plotted. The results presented in this article can be used to control the process of starch pyrodextrinization.