Acid Hydrolysis of Regular Corn Starch under External Electric Field

Abstract

The main objective of the present work is the investigation of a new method for starch hydrolysis. For this, we proposed the acid hydrolysis under the action of an external electric field, able to develop a faster reaction than the conventional one. Corn starch with 18% amylose was subjected to a fixed voltage, varying the external electric field application time and the number of cycles. Morphology, crystallinity, and thermal stability of the starches were investigated by optical and scanning electron microscopy (SEM), X-ray diffraction (XRD), and small-angle X-ray scattering (SAXS). The results showed that the acid hydrolysis coupled with an external electric field allows a significant reduction in hydrolysis time, due to the orientation of the electrolyte ions. Cavities were observed at the surface of hydrolyzed starches after treatment. However, the principal feature is related to the increase of the granule crystallinity with increasing hydrolysis time. The results suggest that the starches treated by this new method are interesting candidates for application in the food industry if greater gelatinization resistance is required.

Starch-Reinforced Vinylogous Urethane Vitrimer Composites: An Approach to Biobased, Reprocessable, and Biodegradable Materials

“…Tensile tests showed increased brittleness by measuring a higher E-modulus and lower tensile strength after chemical recycling (SI, S35-S1). The acidic degradation of starch was intensively investigated in literature and depends on factors like pH, temperature, and time, allowing either an extensive destruction of the starch to smaller building blocks (nanocrystals, oligosaccharides) or only a slight superficial change, regenerating the starch granules and easily separate them from the soluble vitrimer matrix. − Therefore, further investigations on chemical recycling routes of starch-based composites can be conducted, offering several ways for mechanical and chemical reprocessing.…”