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

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 degrees 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.

Automated summary

The structural disorganization of different starches in an aqueous ionic liquid (IL) solution is influenced by the surface characteristics of the granules. Normal cereal starches are easily affected, pea starch is destructed within 6 hours, while high-amylose maize starch and others with dense outer layers are more resistant.