Glass transition temperature of starch studied by a high-speed DSC

The glass transition temperature (T-g) of corn starch was measured using a high-speed DSC with heating rate up to 250 degrees C/min. The high heating rate allows the weak T-g of starch to be visible since the high rate increases the sensitivity of thermal events. For example, the T-g of gelatinized corn starch containing about 13% moisture is too weak to be detected when the heating rate is lower than 50 degrees C/min, but is clearly visible when the heating rate is higher than 100 degrees C/min. Specifically, the technique was used to study the T-g of corn starch film with different moisture contents. The true T-g was calculated by the linear regression equation through plotting the results from different heating rates. (c) 2009 Elsevier Ltd. All rights reserved.