Preparation and characterisation of crosslinked waxy potato starch

Using waxy potato starch as the raw material, the preparation, and determination of physical and chemical properties of acetylated distarch adipate (ADA) were studied systematically. The experimental variables investigated include temperature, pH, and reaction time, which all have influence on the degree of substitution (DS) of crosslinked waxy potato starch. Results show that the optimal reaction was obtained at a pH range of 9.0-9.5, a temperature of 35 degrees C, and a reaction time of 2 h, The structures of ADA starch were characterised by FT-IR, and the results indicate a new absorption peak at 1732 cm(-1) which is assigned to the C=O stretching vibration. It was found through polarised light microscopy and scanning electron microscopy (SEM) that the starch granule structure did not substantially change after crosslinking. The modified waxy potato starch paste exhibited excellent viscosity stability, acid resistant, salt tolerance properties and good breakdown. The swelling of ADA starch granules was gradual over a wide range of temperatures. (C) 2008 Elsevier Ltd. All rights reserved.