Caracterización de proteínas de almacenamiento en la semilla del olivo y en subproductos de la extracción de aceite

Olive seeds contain large amounts of seed storage (SSPs) characterized as globulins of the 11S type, similar to legumins. Legumins are relevant proteins for living processes in plants. Moreover, they are important ingredients for animal and human nutrition, although they have been involved in food allergy. The presence of SSPs of the 11S type hs been detected in several solid residues produced by industries of oil production. As a first step to analyze the potential of these proteins like carbon and nitrogen sources for animal feeding, we have investigated the protein profiles of three products originated after processing of olive stones obtained by de-stoning fruits in an olive processing industry: endocarp and seed fragments (product 1), whole seeds (product 2) and the solid residue resulting from the extraction of soil from seeds (product 3). Analysis of the protein profiles revealed the presence of a large amount of 11S protein in the three products, which was confirmed by immunoblotting. The experiments were performed under denaturing, non-reducing conditions (which revealed the presence of two precursors Pre and Pre2, of 47.5 and 41 kDa) and under denaturing, reducing conditions. Similar analysis of the protein extracts from products 1, 2 and 3 after trypsinolysis and pepsinolysis, displayed that both the precursors Pre1 and Pre2 and the peptides p1 to p5 are practically degraded in a short period of time. The action of the enzymes also produced a degradation of the 11S proteins accumulated in protein bodies in the olive endosperm which was visible by using histological techniques. Potential allergenicity of the olive SSPs of the 11S-type was also analyzed by using the sera from patients allergic to dry fruits. Sera were used in immunoblotting and ELISA experiments, which were able to demonstrate a diminishment of sera’s reactivity to the 11S proteins after trypsinolysis and pepsinolysis. The results obtained indicate that the 11S proteins are easily digested, therefore representing potential ingredients for animal feeding.