Effects of hydrocolloids and freezing rates on freeze–thaw stability of tapioca starch gels

Retrogradation in frozen starch gels was affected by hydrocolloid addition and freezing rate. A freeze–thaw cycle (FTC) treatment was used in this study to determine the effects of hydrocolloids and freezing rates on the stability in tapioca gels. Analysis of retrogradation of starch gels, determined by FTC and based on syneresis measurements, showed that xanthan gum (XG) at 0.25% and 0.50% concentrations was more effective in reducing syneresis than locust bean gum and konjac-glucomannan. Guar gum had no effect in retarding retrogradation of tapioca starch gel. When various freezing rates were used, the results showed that a fast freezing rate (2.30 °C/min) could prevent changes that occurred due to retrogradation more than medium (0.90 °C/min) and slow (0.06 °C/min) freezing rates. The best conditions for the reduction of starch retrogradation in this study was the addition of 0.50% XG with the freezing rate at 2.30 °C/min.