This paper presents an affordable methodology for the analysis of the crosslinking, by polycondensation reaction, between maltodextrin and citric acid under thermal processing. This methodology is based on three complementary analytical techniques: Fourier Transform Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and rheometry. FTIR has been found to be a powerful technique for the characterization of both the esterification reaction and other non-covalent interactions between maltodextrin and citric acid. TGA has been mainly applied to quantify the progress of the polycondensation reaction. Rheometry has been extensively used to understand the crosslink formation resulting from the polycondensation process between maltodextrin and citric acid, allowing the determination of the gel time. Furthermore, these techniques have revealed added value when used as complementary techniques. For instance, the FTIR results supported the conclusions from the study of polycondensation reaction progress by TGA. Similarly, the TGA results about the polycondensation reaction temperature are consistent with the rheology study. Overall, the insightfulness and accuracy of the methodology presented in this paper make it very useful as a tool to optimize industrial processing of materials which apply binding systems based on maltodextrin and citric acid.

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The study of the effect of CaO in the thermal crosslinking of maltodextrin with citric acid demonstrates that the addition of small amount of this compound enhances the crosslinking of the cured system under processing conditions. This enhancement of the crosslinking leads to a noticeable improvement of the mechanical properties. The mechanism of the enhanced crosslinking reaction has been deeply analyzed by rheology, FT‐IR, and TGA. The rheological results show that CaO contributes to the crosslinking. This contribution would allow decreasing 10 °C the temperature of curing process. The enhancement of the crosslinking and consequent improvement of mechanical properties is explained by the contribution of the interactions between the Ca2+ and citric acid and the polycondensate network formed between maltodextrin and citric acid. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44203.