Dodecenyl succinylated guar gum hydrolysate as a wall material for microencapsulation: Synthesis, characterization and evaluation

The esterification of guar gum hydrolysate (GGH) by dodecenyl succinic anhydride (DDSA) was optimized to a degree of substitution (DS) of 0.029 by performing the reaction at 45 °C for 2 h using 3% DDSA (w/w basis of GGH) with added 0.5 g of NaHCO3. The GGH-DDSA ester formation was confirmed by FTIR. The emulsification and subsequent microencapsulation of soybean oil by GGH-DDSA vis-à-vis gum Arabic (GA) and n-octenyl succinylated ester of GGH (GGH-OSA) as wall materials was compared. All the three wall materials stabilised the emulsions over 24 h, their spray dried microcapsules showed smooth surface without fissures, and microencapsulation efficiency was in the order of GGH-DDSA (DS 0.029) = GA > GGH-OSA (DS 0.07). The higher chain length of DDSA over OSA was advantageous for microencapsulation of lipophilic core. GGH-DDSA can be a potentially effective and efficient replacement for GA for encapsulation of lipophilic constituents.