Structural disorganization of cereal, tuber and bean starches in aqueous ionic liquid at room temperature: Role of starch granule surface structure

Ke Zan; Jinwei Wang; Fei Ren; Jinglin Yu; Shuo Wang; Fengwei Xie; Shujun Wang

doi:10.1016/j.carbpol.2021.117677

Structural disorganization of cereal, tuber and bean starches in aqueous ionic liquid at room temperature: Role of starch granule surface structure

Carbohydr Polym. 2021 Apr 15:258:117677. doi: 10.1016/j.carbpol.2021.117677. Epub 2021 Jan 23.

Authors

Ke Zan¹, Jinwei Wang¹, Fei Ren¹, Jinglin Yu¹, Shuo Wang², Fengwei Xie³, Shujun Wang⁴

Affiliations

¹ State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, 300457, China; School of Food Science and Technology, Tianjin University of Science & Technology, 300457, China.
² Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin, 300071, China.
³ International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry, CV4 7AL, United Kingdom. Electronic address: D.Xie.2@warwick.ac.uk.
⁴ State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin, 300457, China; School of Food Science and Technology, Tianjin University of Science & Technology, 300457, China; College of Biological and Chemical Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China. Electronic address: sjwang@tust.edu.cn.

PMID: 33593553
DOI: 10.1016/j.carbpol.2021.117677

Abstract

The structural disorganization of different starches in a 1-ethyl-3-methylimidazolium acetate ([Emim][OAc])/water mixture (1:6 mol./mol.) at room temperature (25 °C) was studied. For normal cereal starches, which have pinholes randomly dispersed on the granule surface or only in the outermost annular region (wheat starch), the aqueous ionic liquid (IL) completely destroyed the granule structure within 1-1.5 h. Pea starch (PeS) granules with cracks were destroyed by the aqueous IL within 6 h. High-amylose maize starch (HAMS), as well as potato and purple yam starches (PoS and PYS), which have a dense and thick outer granule layer, were even more resistant to the action of the solvent. Structural disorganization was accompanied by increased viscosity and controlled the binding of water molecules with starch chains. From this study, we concluded that the surface characteristics of starch granule are an important factor affecting starch structural disorganization in an aqueous IL.

Keywords: Aqueous ionic liquid; Crystalline structure; Different starch cultivars; Granule structure; Starch dissolution; Starch granule destruction.