Influence of cooling rate on glass transition temperature of sucrose solutions and rice starch gel

The study's objectives were to determine the influence of cooling rate through the primary zone of freezing on T(g) in sucrose solutions and rice starch gels. The influence of cooling rate, water content, and annealing on T(g) were evaluated. Results indicated that the observed T(g) values for sucrose solutions were lower after rapid cooling (70% solids: rapid cooling -66.7 degreesC; slow cooling -64.6 degreesC; 30% solids: rapid cooling 34.6 degreesC; slow cooling -33.3 degreesC). The T(g) values of annealed samples are higher than the T(g) of both rapidly and slowly cooled samples (70%: -44.2 degreesC; 30%: -32.7 degreesC). The T(g) of the rice starch gel wags -9.0 degreesC after rapid cooling and -7.5 degreesC after slow cooling.