Evaluation of the degree of starch pyrodextrinization by binary digital image colorimetry

Dextrins are widely used in the food, textile, paper, mining, chemical and pharmaceutical industries. Pyrodextrin is one of the most known representatives of these materials. Its production is based on the heat treatment of starch in the absence of a catalyst. A significant demand for pyrodextrin, as well as an increase in the scope of its application, necessitates the improvement of existing methods of quality control of this material. The main parameter characterizing the solubility, viscosity and intensity of color is the degree of starch pyrodextrinization. The evaluation of this parameter in conditions of industrial production is carried out by visual observation. The use of such organoleptic methods leads to significant measurement errors. In this study, we have summarized information about the mechanism of starch pyrodextrinization, and considered the effect of the temperature and heating time on the color intensity of the resulting dextrins. A method of binary digital image colorimetry is proposed to be used for assessing the degree of starch pyrodextrinization, i.e., to measure the level of binarization of dextrins with subsequent determination of this parameter, taking into account the initial assumptions. The possibility of using a specialized software for quantitative analysis of images for the purpose of their transformation and subsequent determination of the binarization level of the studied dextrins is shown. The significance of the effect of temperature and heating time on the degree of starch pyrodextrinization was shown by analysis of variance (ANOVA). The mathematical description of the dependence of these parameters was obtained by multiple regression. The results presented in the study confirm the applicability of binary digital image colorimetry to assessing the degree of starch pyrodextrinization and process control.