Studies on Acacia seyal gums from Sudan: effect of tree age and exudates form on the tannin level

Acacia Seyal is the most important supplier for gum Arabic a natural polysacharides that drips out of the cracks of the bark and solidifies. The brown color of Acacia. seyal gum is due to presence of tannin. The factors that affect the tannin level in Acacia. seyal gums (different exudates) var. fistula and var. seyal) grown in Sudan (Sennar area) were determined and varieties in their properties evaluated. Tannin content was determined using tannin content method. The results showed that the effect of variants (two variants), age (old and young trees) and types of exudates (nodule, seeping and lumps) affect tannin contents. In evaluating the result, tannin content was maximum in seeping gum (0.11-0.29) and there was variation with varieties and age of the trees, The results for physiochemical properties moisture, ash, nitrogen, protein, viscosity, pH and specific rotation were determined and showed that physiochemical properties for seeping gum var. fistula and var. seyal old and young differ from nodule and irregular gum type. Cationic contents showed that the abundance of the alkali and alkaline earth metals in Acacia. Seyal gum exudates follow the trend Ca > Na >K, except seeping, irregular and nodule in var. fistula old and young respectively. The iron content was high in nodule gum in both varieties old and young age. In case o f Acacia. seyal var. fistula young age, the seeping gum had higher iron content than irregular and nodule type.