2026-04-27T12:51:19Zhttps://uvadoc.uva.es/oai/request

oai:uvadoc.uva.es:10324/833312026-03-05T20:01:57Zcom_10324_31661com_10324_952com_10324_894col_10324_31662

Molecular basis of changes in pasting and rheological properties of starches physically modified by microwave radiation Mauro, Raúl Ricardo Li, Zhihang Blennow, Andreas Vicente Fernández, Ainhoa Ronda Balbás, María Felicidad Producción Científica This study investigates the effects of controlled microwave treatment (100 ◦C, 25% moisture, 30 min) on the molecular and rheological properties of pure starches (normal and waxy maize, normal and waxy rice, wheat, potato and tapioca). Structural changes were assessed through high-performance anion exchange chromatog- raphy with pulsed amperometric detection (HPAEC/PAD) to resolve amylopectin chain-length distributions, and size-exclusion chromatography with multi-angle light scattering, differential refractive index, and viscometric multi-detection (SEC/MALS-dRI-Visco) to determine amylose and amylopectin molecular parameters for both debranched and whole molecules. The impact of these changes on the pasting properties of starches and the viscoelasticity of their gels was established. Microwave treatment induced source-specific responses. Waxy starches showed increases in very short amylopectin chains and molecular degradation, with minimal rheological impact due to their low viscometric profile. Potato starch experienced the most pronounced rheological modi- fications despite minimal molecular degradation, suggesting supramolecular reorganisation, supported by an increase in amylopectin intrinsic viscosity. Wheat and tapioca starches exhibited moderate structural changes and enhanced gel stability, attributed to an increase of fractions comparable in size to long amylopectin chains. Rice starches displayed similar pasting and rheological responses, having amylopectin fine structure a pre- dominant role, while the absence of amylose in waxy rice favoured greater amylopectin hydrolysis. Correlation analyses linked amylose short/medium chains to parameters related to stronger and firmer gels. In contrast, short amylopectin chains correlated with weaker gels. These findings offer mechanistic insight into the potential of controlled microwave processing to tailor starch functionality in food systems. 2026-03-05T10:31:41Z 2026-03-05T10:31:41Z 2026 info:eu-repo/semantics/article Food Hydrocolloids, 2026, vol. 176, p. 112581 0268-005X https://uvadoc.uva.es/handle/10324/83331 10.1016/j.foodhyd.2026.112581 112581 Food Hydrocolloids 176 eng https://www.sciencedirect.com/science/article/pii/S0268005X26001633 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by-nc-nd/4.0/ © 2026 The Author(s) Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier SI