Effect of shell separation pretreatment on the physicochemical properties of octenyl succinic anhydride-modified starch.

The effects of shell separation pretreatment (SSP) on the physicochemical properties of octenyl succinic anhydride (OSA)-modified starch were investigated in this study. SSP at different temperatures promoted esterification between starch molecules and OSA and thereby achieved a higher degree of substitution (DS). OSA-modified granule shells (OSC) exhibited a rough surface and irregular shape, which were attributed to swelling caused by SSP during modification processes. The paste viscosity and viscoelastic properties of OSC were enhanced after SSP. Both the swelling power and transparency of OSA esterified starch increased with DS values after SSP. The content of resistant starch (RS) among OSA esterified starch increased from 33.18 % to 45.33 %, which mainly occurred when SSP was introduced into the OS starch synthesis process. In summary, SSP at different temperatures promoted the unique physicochemical properties of OSC specimens by increasing their DS values.