Lipid compositions of latex and sheet rubber from Hevea brasiliensis depend on clonal origin

Lipids of fresh latex from three Hevea brasiliensis clones (RRIM600, BPM24, and PB235), and of sheet rubber produced from it, were extracted by an optimized method and characterized through various chromatography techniques. Total and free fatty acids, phospholipids, glycolipids, and the unsaponifiable fraction were analyzed for each clone. Qualitative and quantitative comparisons of total extractable lipids indicated a smaller amount in sheet rubber (2.31-3.28%?w/w dry rubber) than in fresh latex (3.36-3.67%). Partial hydrolysis during primary rubber processing, such as polar lipids, was found to be the main source of this loss. Alongside the effect of primary processing, the clonal origin of the trees was found to be the main factor for differences in lipid quantity and composition. Practical applications: Lipids are the main non-isoprene components in natural rubber (NR) and play many important roles in NR properties. Detailed knowledge of the lipid composition would contribute towards a better understanding of the structural and physical properties of NR. The lipid composition also appears to be sufficiently specific to consider its use as a new tool for tracing the clonal origin of NR. (Résumé d'auteur