Electrosynthesis-driven fractionation and structural remodeling of corn starch: Implications for molecular architecture, thermal behavior, and digestibility
Academic Article in Scopus
Electrosynthesis-assisted fractionation was evaluated as a non-thermal strategy to differentiate and structurally remodel corn starch assemblies, using physical sedimentation and targeted enzymatic hydrolysis as comparative treatments. Commercial corn starch was gelatinized and treated with ¿-amylase or isoamylase before electrosynthesis-assisted separation into light and heavy fractions. Physical sedimentation revealed intrinsic heterogeneity within gelatinized corn starch, generating fractions with different mass recovery, ConA-derived apparent amylose content, thermal behavior, molecular-size distribution, colloidal stability, and in vitro digestibility. Enzymatic treatments further amplified these differences through pathway-specific remodeling. ¿-Amylase promoted molecular disassembly and generated highly digestible fractions, whereas isoamylase debranching favored the redistribution of linear and longer-chain glucan populations with greater potential for reassociation. Electrosynthesis was associated with additional structural differentiation, reflected by changes in HPSEC-MALLS molecular-size profiles, debranched HPSEC chain-length distributions, DSC thermograms, and colloidal behavior. These effects were most evident when electrosynthesis was combined with isoamylase, particularly in the light fraction, which showed increased levels of slowly digestible and resistant starch and the lowest predicted glycemic index among the evaluated samples. Exploratory PCA and predictive PLSR analyses supported associations among molecular size, chain-length architecture, thermal stability, and responses to digestibility. Overall, electrosynthesis-assisted fractionation appears to be a promising non-thermal approach for generating corn starch fractions with distinct structural, thermal, colloidal, and in vitro digestibility profiles. However, the electrokinetic phenomena proposed to contribute to these changes require direct validation in future studies.
