Response surface methodology Was Used to analyze the effect of amylase level (X-1) and glycerol level (X-2) on the objective [water solubility index (WSI), water absorption index (WAI), and Max. loading] attributes of a poly(vinyl alcohol)-/cornstarch-blended composite. A rotable central-composite design (CCD) was used to develop models for the objective responses. The experiments were run at die temperature 100 degrees C with a feed rate of 25 g/min and a screw speed of 35 rpm. Responses were most affected by changes in the amylase level (X-1) and to a lesser extent by glycerol level (X-2). Individual contour plots of the different responses were overlaid, and regions meeting the optimum WSI of 3.03 (%), WAT of 5.08 (g gel/g dry wt), and Max. loading of 29.36 (N) were identified at the amylase level of 2.8 (mL) and the glycerol level of 92.2 (mL), respectively. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 258-264, 2009