Simple thermal and freezing treatments to improve absorption capacity and alter digestibility of canna starch granules.

Swollen canna starches (SCS) were prepared by controlled heating of unmodified and heat-moisture treated (HMT) starch suspensions at sub-gelatinization temperatures; subsequently, freezing was conducted to stabilize the structure of the SCS. Sizes of both unmodified and HMT swollen granules increased with increasing heating temperatures (up to 2.5 times), and freezing resulted in a significant reduction of granular size. The absorption capacities of the swollen starches increased up to 6 times for water and 3 times for tributyrin and palm oil compared to unmodified starch. The differences in absorption capacities of the unmodified and HMT swollen starches were small. Freezing the swollen starches tended to decrease oil and water absorptions, except for unmodified starch swollen at 70 °C, where freezing increased water absorption. Freezing significantly decreased the susceptibility of the swollen unmodified starches to amylase digestion and slowed down the digestion of the swollen HMT starches.

Preparation of thin-film electrolyte from chitosan-containing ionic liquid for application to electric double-layer capacitors.

A novel thin-film electrolyte (TFE) based on chitosan (CS) with 1­ethyl­3­methylimidazolium tetrafluoroborate (EMImBF4) was prepared by a new procedure for use as a solid electrolyte in electric double-layer capacitors (EDLCs). In this system, EMImBF4 plays important roles as both a dissolving solution and a charge carrier for EDLC application. By analyzing and characterizing the obtained products, the CS-TFEs showed a surface without CS/EMImBF4 phase separation and with high thermal stability and good tensile properties. The electrochemical properties were measured as the charge-discharge performance, the discharge capacitance, and alternating-current impedance. A test cell with CS-TFE with a calculated dry thin-film content of 80 wt% EMImBF4 showed a comparable IR drop and higher discharge capacitance than a liquid-phase EMImBF4 system and also showed low electrode/electrolyte interfacial resistance. Consequently, this novel CS-TFE is suitable for high-performance EDLCs and improves the safety of such devices.