Polymeric biophenols in olive mill wastewaters
Olive mill wastewater (OMW), the effluents generated in the olive (Olea europaea L.) oil extraction industry operating in three-phases mode, are phytotoxic mainly due to its high phenolic content . On the other hand, attending to the potential health-benefits of some of their phenolic compounds, OMW are now regarded as a potent source of biophenols for food and pharmaceutical industries. An important portion of the OMW biophenols include the secoiridoids found in olive pulp and their derivatives formed along the olive oil extraction process . Still, due to the complex composition of OMW, many phenolic compounds remain unknown. Their structural identification can encourage the search of new bioactive compounds in OMW and contribute to further valorize this waste.
In the present work, electrospray ionization-mass spectrometry analysis in the negative mode with direct infusion of OMW aqueous acetone purified extracts allowed to identify new major polymeric compounds, detected as [M-H]- ions at m/z 909, 1071, 1457, 1075 and 1613. These compounds could be classified into two groups: I- derivatives of a ligstroside glucoside isomer and II- oleuropein oligomeric compounds. Attending that the scavenging ability of a polyphenolic compound is increased by its degree of polymerization , bioactivities related to that capacity are expected at least for some of these compounds.
Acknowledgement: Work supported by Fundação para Ciência e a Tecnologia, project Biotechnological valorization of olive mill wastewaters (OMWalor) – PTDC/AMB/69379/2006
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