Influence of corn starch type in the rheological properties of a white sauce after heating and freezing

The freeze/thaw and heating stability of white sauces prepared with two modified waxy corn Starches (hydroxypropyl distarch phosphate and acetylated distarch adipate) and two native corn starches (waxy and normal) are compared. The viscoelastic properties of the sauces prepared with both types of modified starches were not affected by a freeze/thaw cycle or by subsequent heating up to 80 degrees C. On the other hand, in the native corn starch sauces, especially in the normal corn starch, the freeze/thaw cycle produced a significant increase in the linear viscoelastic functions. In the normal native starch sauce also the appearance of syneresis was observed. However, in both native starch sauces these structural changes were substantially recovered upon heating after thawing. The effect of the freeze/thaw cycle was lower in the native waxy corn starch due to its lower amylose content, which reduced retrogradation. In all the fresh white Sauces, heating until 80 degrees C practically did not affect the viscoelastic properties neither produced syneresis. (C) 2008 Elsevier Ltd. All rights reserved.