Derivatisation of Cashew Gum by Esterification Using Citric Acid and Glycerol

Citric acid and glycerol were used to derivatise cashew gum via cross-linking. A dispersion of the purified gum, the acid, glycerol and sodium dihydrogen phosphate was made in deionised water and concentrated by heating at 40ºC for 18 h. The resulting solid mass was heated at 140ºC/170ºC for 30 min for the cross-linking to take place. The cross-linking was demonstrated using DSC, FT-IR and NMR spectral data and the esterified derivative (tagged CrosCCG) was characterized by determination of the solubility, water content, swelling and water holding capacity, moisture sorption and desorption, particle flow properties The results obtained indicated that the cross-linked product differed from the parent gum and from cashew gum cross-linked using citric acid alone, by displaying greater swelling ratios, water sorption and water holding capacities. This product may find use as swellable device in controlling drug release or as disintegrant in pharmaceutical and biomedical applications.