This paper explores the molecular mechanisms involved in residual stress in relation with shape memory effects in glassy amorphous starch. Wide-angle X-ray scattering (WAXS) and synchrotron radiation (SR) polarized infrared microspectroscopy were used to analyze the structural anisotropy revealed by polarized light microscopy. A local molecular orientation was evidenced by WAXS and 1 R dichroism. Results clearly demonstrate that the residual stress observed in the temporary shape is due to local molecular orientation in amorphous starch resulting from the flow of matter induced by the deformation process. The molecular orientation disappears when the sample relaxes and recovers its initial shape