Esterification of pea starch with octenyl succinic anhydride using conventional and microwave irradiation method: synthesis and characterization

The purpose behind this investigation was to modify native pea starch by means of the microwave-assisted and conventional method of esterification by utilizing octenyl succinic anhydride (OSA) as esterifying agent and investigation of structural as well as its functional properties. The present investigation shows the direct esterification of pea starch using OSA (esterified-starch) under alkaline conditions to activate the native pea starch and followed by terminating the esterification process of starch by maintaining acidic conditions. Starch esters, containing amphiphilic groups are well known to enhance emulsification properties, and after hydrolysis employed for encapsulation. The esterification of pea starch was confirmed by FTIR and nuclear magnetic resonance. Structural changes were confirmed by XRD, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and by molecular weight determination. Some functional properties were investigated by performing emulsification capacity, oil absorption capacity, emulsion stability, transparency, and viscosity determination. Both OSA-modified starches were compared with native pea starch. Esterification of pea starch with OSA enhanced the emulsification with an attractive scope of consistency that makes it appropriate as a divider material for encapsulation.