Effect of sucrose, inverted sugar and phosphate on cassava starch bio-based films: Microstructure, color, water activity and solubility. Part 2

Abstract

Previous studies had indicated that additives such as sucrose, inverted sugar andsodium phosphate have resulted in significant increase on cassava starch films materialselongation. However, crystallization after storage has been reported. In order to evaluatethe effect of such additives (sucrose, inverted sugar and sodium phosphate) on cassavastarch films microstructure, color, water activity and solubility, a response surfacemethodology design experiment has been performed. None of the studied additivesaffected cassava starch water activity, solubility and color (L, a, b and haze)(p<0.05). However, when comparing the experimental samples to the control (cassavastarch film with no additive), an increase on water activity, solubility and total colordifference was observed. X-ray diffractograms and, SEM and light microscopy, haveindicated that inverted sugar can prevent sucrose crystallization if utilized in thecombination of a maximum of 0.8% sucrose and any concentration of inverted sugar, orthe maximum of 1.2% sucrose with 0.4% inverted sugar. Increasing inverted sugar andphosphate concentration leads samples to a semi-crystalline behavior. Inverted sugaraddition probably have resulted in cassava starch crystallites re-organization. Phosphate addition (> 0.48%) affected the gelatinization temperature of the starch presented in the film forming suspension, resulting in a totally amorphous structure. © 2011 by Nova Science Publishers, Inc. All Rights Reserved.