INFLUENCE OF GLASS TRANSITION TEMPERATURE ON RATE OF RICE STARCH RETROGRADATION DURING
An increasing amount of research suggests a relationship between the glass-transition temperature (Tg) and the optimum storage temperature for a frozen food. In addition, the Tg for a frozen food is related to the cooling rate through the temperature range of phase transition for water. The objectives of this study were to investigate the influence of Tgon the rate of starch retrogradation during low-temperature storage. Rice starch with 65% w/w water content was heated to obtain starch gel as a model food. The influences of cooling rate, storage temperature and time on rate of retrogradation were evaluated. Differential scanning calorimetry was used to measure the Tgand the enthalpy during retrogradation. Results indicated that the retrogradation rate during storage was reduced at a slower cooling rate. The retrogradation rates at storage temperatures above Tgwere higher than at storage temperatures below Tg.
Document Type: Research Article
Publication date: October 1, 2005