Rheological, pasting, thermal and retrogradation properties of octenyl succinic anhydride modified potato starch

The objective of the present study was to investigate the rheological, pasting, and thermal properties of octenyl succinic anhydrate (OSA)-modified potato starch. Potato starch was modified using different concentrations of OSA (0, 1, 3, and 5%, v/v). The degree of substitution (DS) for the OSA-modified starch ranged from 0.0012 to 0.0055. The amylose leaching values of native and OSA-modified potato starch with different DS levels were in the range of 47.09-87.32%. The gel strength values of the OSA-modified starch were lower than those of native potato starch. Rapid Visco Analyzer data showed that peak, hot pasting, final and setback viscosities of the native starch decreased after OSA modification. Dynamic shear rheological tests, conducted at 4 degrees C, indicated that OSA-modified potato starch had weak gel-like behavior with the storage moduli (G') higher than the loss moduli (G '') over most of the frequency ranges (0.63-63.8 rad.s(-1)).