Species widely disseminated in Venezuela which produce gum exudates

Venezuela, a tropical country, has many species, widely disseminated, that are able to produce gum in good yield. We have been working on gums from sp ecies belonging to many families. It has been demonstrated that 29 species located in different counties of Zulia State, Venezuela, South America, pro duce gum easily. The gum produced from the studied species was collected a week after the injury was made at trunk level. Most of these gums are very soluble in water and are produced in high yield. The analytical data of gum s from Mimosaceae species were determined. The properties of the gums from Acacia macracantha, A. tortuosa, A. glomerosa, Enterolobium cyclocarpum and Samanea saman are very interesting. The gums from A. macracantha and A. to rtuosa have high solubility, comparable to that reported for A. senegal. Th is behavior contrasts with that of A. glomerosa which forms a gel easily. T he viscosity of E. cyclocarpum (100 ml/g), comparable to some Combretum gum s, is higher than that reported for the Acacia gums studied so far. C-13 NM R spectra of the polysaccharides isolated from these gums showed interestin g structural features. The properties of these Mimosaceae gums may have pot ential economical interest. The proven presence of native species, adapted to the precise ecological conditions, capable of yielding good quality gum offers an opportunity for attention to be given to increasing agroforestry development within Venezuela based on those species. The climatological con ditions of hot arid areas are suitable for commercial gum production in hig h yield. (C) 2000 Elsevier Science Ltd. All rights reserved.