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The induced electric field assisted hydrochloric acid (IEF-HCl) hydrolysis of potato starch was investigated in a fluidic system. The impact of various reaction parameters on the hydrolysis rate, including reactor number (1–4), salt type (KCl, MgCl 2 , FeCl 3 ), salt concentration (3–12%), temperature (40–55 °C), and hydrolysis time (0–60 h), were comprehensively assessed. Under optimal conditions, the maximum reducing sugar content in the hydrolysates was 10.59 g/L. X-ray diffraction suggested that the crystallinity of IEF-HCl-modified starches increased with the intensification of hydrolysis but was lower than that of native starch. Scanning electron microscopy indicated that the surface and interior regions of starch granules were disrupted by the hydrolysis. The solubility of IEF-HCl-modified starches increased compared to native starch while their swelling power decreased, contributing to a decline in paste viscosity. These results suggest that IEF is a notable potential electrotechnology to conventional hydrolysis under mild conditions without any electrode touching the subject. [ABSTRACT FROM AUTHOR]

This study aimed to improve induced electric field (IEF)-assisted hydrolysis of polysaccharide by controlling electrical conductivity. As the conductivity of reaction medium was increased, the energy efficiency of IEF was increased because of deceased impedance, as well as enhanced output voltage and temperature, thus the hydrolysis of guar gum (GG) was accelerated under IEF. Changes in weight-average molecular weight (Mw) suggested that IEF-assisted hydrolysis of GG could be described by the first-order kinetics 1/Mw ∝  k t, with the rate constant ( k ), varying directly with the medium conductivity. Although IEF-assisted hydrolysis largely disrupted the morphological structure of GG, it had no impact on the chemical structure. In comparison to native GG, the steady shear viscosity of hydrolyzed GG dramatically declined while the thermal stability slightly decreased. This study extended the knowledge of electrical conductivity upon IEF-assisted acid hydrolysis of GG and might contribute to a better utilization of IEF for polysaccharide modification. [ABSTRACT FROM AUTHOR]

• IEF-assisted hydrolysis enhanced with increasing DD of chitosan. • Electrical properties of chitosan showed no significant effect on the hydrolysis. • Structural compactness determined the hydrolysis behavior of different-DD chitosan. This study explored the impact of re-acetylation on induced electric field (IEF)-assisted hydrolysis of chitosan. Chitosan with different degree of deacetylation (DD) exhibited different charge content but similar electrical conductivity and output voltage of the electrolyte system, thus theoretically resulting in equivalent electro-processing efficiency. However, molecular and rheological measurements suggested that the hydrolysis rate decreased with an increase of DD. Re-acetylation had no significant effect on the molecular weight and viscosity of chitosan but damaged its granular and crystal structure, making chitosan chains more susceptible to the acid. The IEF-assisted hydrolysis of dissolved chitosan confirmed that the structural compactness of chitosan played a more important role on the hydrolysis than the charge content. This study extended current knowledge regarding the effect of charge content and structural compactness on IEF-assisted hydrolysis process, which contributed to the applications of IEF in biopolymer modification. [ABSTRACT FROM AUTHOR]