The present work accomplished the determination of seleno-amino acids bound to proteins in olive oils. The organic solvent mixture, acetone:n-hexane, at low temperature, showed the best performance for protein extraction from EVOOs, in comparison with other extraction methods tested.
SEC–ICP-MS exhibited enough separation capacity and sensitivity to identify Se–S fractions correspondent with proteins‘ molecular weight. Collection of these fractions, along with protein concentration, encompass SEC–ICP MS analysis, through MAAH, with RPC–ICP MS determination. In this way, a sequence of extraction and separation steps reached enough selectivity and sensitivity for determination of seleno-amino acids integrated to proteins, in a complex matrix.
Determination of free and protein-bound seleno-amino acids in olive oils is relevant from a nutritional point of view considering their different bioavailability, and the role of selenium in the reduction of oxidative stress. This research validates the knowledge that olive oil consumption is associated with a decrease of the incidence of important human illnesses.
This paper provides useful data for further research on the use of protein fractions as a tool for cultivar origin differentiation of EVOOs.