Studies on the moisture sorption characteristics of poly(vinyl alcohol)/starch blends for water activity (a(w)) values of 0.1-0.9 were performed at 27degreesC. The equilibrium moisture content at different a(w) values was used to fit different sorption isotherm models proposed in the literature. The ranges of a(w) applicable for the different sorption isotherms were reported. The model constants of the sorption equations were determined by linear fitting. The value of the coefficient of determination (0.98 +/- 0.01) confirmed the goodness of fit of the equations studied. (C) 2003 Wiley Periodicals, Inc.