TY - JOUR
T1 - Phase transition of maize starch in aqueous ionic liquids
T2 - Effects of water:ionic liquid ratio and cation alkyl chain length
AU - Ren, Fei
AU - Xie, Fengwei
AU - Luan, Huiyu
AU - Wang, Shuo
AU - Wang, Shujun
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/2
Y1 - 2020/2
N2 - The thermal phase transition behavior of maize starch in water:ionic liquid (IL) mixtures was investigated. With decreasing water:IL molar ratio to 10:1, the endothermic transition shifted to higher temperatures, and then to lower temperatures at 5:1 water:IL ratio. At 2:1 water:IL ratio, an exothermic transition occurred at a lower temperature than gelatinization temperature of starch in pure water. At the same water:IL ratios (35:1 to 5:1), the endothermic transition temperatures of starch increased with decreasing alkyl chain length of the cation, whereas an opposite trend was found for the exothermic transition at 2:1 water:IL ratio. Rheological, 1H NMR and FTIR analyses of water:IL mixtures showed that with decreasing water:IL ratio, the viscosity of water:IL mixture and the interactions between cation and anion increased, whereas the interactions between IL and water increased and then decreased. The endothermic transition of starch in water:IL mixtures of 35:1 to 5:1 was affected by the water availability for gelatinization. However, the exothermic transition of starch in water:IL mixtures of 2:1 was mainly caused by the interactions between IL and starch and viscosity of water:IL mixtures.
AB - The thermal phase transition behavior of maize starch in water:ionic liquid (IL) mixtures was investigated. With decreasing water:IL molar ratio to 10:1, the endothermic transition shifted to higher temperatures, and then to lower temperatures at 5:1 water:IL ratio. At 2:1 water:IL ratio, an exothermic transition occurred at a lower temperature than gelatinization temperature of starch in pure water. At the same water:IL ratios (35:1 to 5:1), the endothermic transition temperatures of starch increased with decreasing alkyl chain length of the cation, whereas an opposite trend was found for the exothermic transition at 2:1 water:IL ratio. Rheological, 1H NMR and FTIR analyses of water:IL mixtures showed that with decreasing water:IL ratio, the viscosity of water:IL mixture and the interactions between cation and anion increased, whereas the interactions between IL and water increased and then decreased. The endothermic transition of starch in water:IL mixtures of 35:1 to 5:1 was affected by the water availability for gelatinization. However, the exothermic transition of starch in water:IL mixtures of 2:1 was mainly caused by the interactions between IL and starch and viscosity of water:IL mixtures.
KW - Alkyl chain length
KW - Ionic liquid-water mixture
KW - Molecular interactions
KW - Starch phase transition
KW - Water availability
UR - http://www.scopus.com/inward/record.url?scp=85076402608&partnerID=8YFLogxK
U2 - 10.1016/j.indcrop.2019.112043
DO - 10.1016/j.indcrop.2019.112043
M3 - Article
AN - SCOPUS:85076402608
SN - 0926-6690
VL - 144
JO - Industrial Crops and Products
JF - Industrial Crops and Products
M1 - 112043
ER -