The nuclear magnetic resonance spectroscopy (NMR) studies of starches obtained by fruit seeds such as melon and watermelon were carried out as an analytical methodology to understand the molecular dynamic behavior. This study was also accompanied by the conventional X-ray diffraction and thermal analysis. The NMR results give us a complete behavior of the samples at the molecular level. Thus, the information obtained from NMR will complement the data obtained from X-ray and thermal analysis allowing us having responses on samples structure and dynamical behavior. (C) 2007 Wiley Periodicals, Inc.