Characterisation and properties of Acacia senegal (L.) Willd. var. senegal with enhanced properties (Acacia (sen) SUPERGUM™): Part 4. Spectroscopic characterisation of Acacia senegal var. senegal and Acacia (sen) SUPERGUM™ arabic

The series of control Acacia senegal gums and the samples which had been matured to produce the Acacia (sen) SUPERGUM™ samples (FR-2877, FR-2878, FR-2879) described in Part 1–3 of this Series were examined by NMR, FT-IR spectroscopy. No chemical difference in any of the samples could be detected by 13C NMR or 2D NMR (COSY) spectroscopy. The 1H NMR and FT-IR spectra confirming these observations, however, showed that at the highest level of maturation to average molecular weights in excess of 2.5×106, some changes could be observed, which probably is due to dehydration of the carboxyl group (–COOH) of the uronic acid. The selection of matured gums for commercial use ensures that no observable changes in structure are evident in these gums.