Synthesis and physicochemical evaluation of octenylsuccinated kappa-carrageenan: Conventional versus microwave heating.

This research reported on the synthesis and the evaluation of new octenyl succinate (OS) kappa-carrageenan (KC) esterified derivatives (KC-OS). Two derivatives were synthesized using microwave (KC-OSMM) and conventional heating (KC-OSCM). The FT-IR and H NMR demonstrated the KC-OS esters formation with a higher degree of substitution for KC-OSMM (0.85) than KC-OSCM (0.62). The SEM testing showed the non-deteriorated morphology of KC after modification. The amphiphilic properties and surface activity of KC-OSs investigated by the conductivity method confirmed the formation of self-assembled aggregates beyond a critical aggregation concentration of 0.08% for KC-OSMM and 0.12% for KC-OSCM. Stable oil-in-water emulsions were formulated based on KC-OSs at the concentrations of 0.75% and 1%. Lower globule sizes were observed for KC-OSMM emulsions at 0.75% (12.30 μm) and 1% (08.86 μm), compared to KC-OSCM at 0.75% (32.75 μm) and 1% (19.6 μm). All results demonstrated that microwave synthesis resulted in obtaining novel derivatives with superior properties.