Acknowledgements
This manuscript is prepared from MSc. thesis of first author
at University of Tr´as-os-Montes e Alto Douro. We are grateful
to AGRUPALTO producers association for support. We also
thanks to Francisco Fagundes from MSD – Merck Sharp &
Dohme, Lda, Paço de Arcos, Portugal and to Mar´ıa Luisa
Mart´ınez Sanz from LABOPAT, Segovia, Spain for their technical/
laboratorial support