Real-time monitoring of the starch cross-linking with citric acid by chemorheological analysis

Gustavo A Duarte; Maria C Bezerra; Sílvia H P Bettini; Alessandra A Lucas

doi:10.1016/j.carbpol.2023.120733

Real-time monitoring of the starch cross-linking with citric acid by chemorheological analysis

Carbohydr Polym. 2023 Jul 1:311:120733. doi: 10.1016/j.carbpol.2023.120733. Epub 2023 Feb 23.

Authors

Gustavo A Duarte¹, Maria C Bezerra², Sílvia H P Bettini³, Alessandra A Lucas³

Affiliations

¹ Federal University of Sao Carlos, Graduate Program in Materials Science and Engineering, Rodovia Washington Luiz, Km 235 SP-310, 13565-905 São Carlos, SP, Brazil. Electronic address: gustavoduarte@ppgcem.ufscar.br.
² Federal University of Sao Carlos, Graduate Program in Materials Science and Engineering, Rodovia Washington Luiz, Km 235 SP-310, 13565-905 São Carlos, SP, Brazil; Federal University of Paraiba, Department of Chemical Engineering, 58059-900 João Pessoa, PB, Brazil.
³ Federal University of Sao Carlos, Graduate Program in Materials Science and Engineering, Rodovia Washington Luiz, Km 235 SP-310, 13565-905 São Carlos, SP, Brazil.

PMID: 37028869
DOI: 10.1016/j.carbpol.2023.120733

Abstract

Cross-linking has been used as a strategy to improve the mechanical properties of starch films. However, the concentration of the cross-linking agent and the cure time and temperature determine the structure and properties of the modified starch. This article, for the first time, reports the chemorheological study of cross-linked starch films with citric acid (CA) through monitoring the storage modulus as a function of time G'(t). In this study, a CA concentration of 10 phr showed a pronounced increase of G'(t) during the cross-linking of starch, followed by a constant plateau. Analyses of infrared spectroscopy validated the result chemorheological. In addition, the mechanical properties showed a plasticizing effect of the CA at high concentrations. This research demonstrated that chemorheology is a valuable tool in the study of starch cross-linking, which becomes a promising technique to evaluate the cross-linking of other polysaccharides and cross-linking agents.

Keywords: Chemorheology; Citric acid; Cross-linking; Starch.