ARS | Publication request: Structure and Properties of Corn, Rice, Wheat and Potato Starch Dispersed in the Ionic Liquid, 1-Butyl-3-Methylimidazolium Chloride

Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract
Publication Acceptance Date: September 16, 2006
Publication Date: September 16, 2006
Citation: Stevenson, D.G., Biswas, A., Jane, J., Inglett, G.E. 2006. Structure and properties of corn, rice, wheat and potato starch dispersed in the ionic liquid, 1-butyl-3-methylimidazolium chloride [abstract]. American Association of Cereal Chemists Meetings. p. 158.

Technical Abstract: Ionic liquid has gained industry attention, especially in environmentally friendly green chemistry. Researchers have utilized ionic liquid for dispersing cellulose, but no report using ionic liquid for other polysaccharides. In this study, corn, rice, wheat and potato starches were dispersed in hot water (DIHW) or the ionic liquid, 1-butyl-3-methylimidazolium chloride and morphology, amylopectin molecular weight (APM_w) and thermal properties were analyzed. For starch DIHW, corn and potato had gelatinized aggregates, whereas rice and wheat had granular clumps. Starch heat-dispersed in ionic liquid (HDIIL) had clumps composed of < 1 micrometer diameter particles. Starch DIHW had slight decrease in APM_w of corn and rice starch, but not for wheat or potato starch. Cereal starches had APM_w greatly reduced by HDIIL (4-6 peaks observed). Potato amylopectin was degraded less by ionic liquid (two peaks) probably because negatively-charged phosphomonoesters covalently bonded to positively-charged imidazolium rings or were repelled by ionic liquid chloride ions. The larger granule size of potato starch may also have impeded ionic liquid penetration, reducing reaction efficiency. Thermal properties showed potato starch incompletely gelatinized by HDIIL whereas cereal starches were completely gelatinized. Due to the degradation products observed, our results suggest that industrial applications of ionic liquids involving starch may be limited unless alternative, less destructive, ionic liquids can be found.