Interaction of aspartame with selected hydrocolloids: solubility of aspartame

The interaction of aspartame (APM) with selected hydrocolloids was investig ated observing solution characteristics and using scanning electron microsc opy. The presence of hydrocolloids improved the solubility of APM in the fo llowing decreasing order: CMC and acacia gum > kappa-carrageenan and pectin > locust bean gum > guar gum > xanthan > amylopectin. Thus, low-viscosity solutions of charged hydrocolloids were the most effective in improving APM solubility. The maximum amount of APM which could be held in solution in t he presence of CMC and acacia sum at 5 degrees C was 5.7 and 5.4%, respecti vely. Scanning electron micrographs revealed co-precipitates of APM with th e hydrocolloids and smaller APM crystals than those obtained from the contr ol solution. The mechanism of stabilization of the APM solutions is consist ent with a binding of APM to hydrophobic portions of hydrocolloids, which a re enhanced at the low pH. (C) 1999 Elsevier Science Ltd. All rights reserv ed.