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Evaluation of lignans and free and linked hydroxy‐tyrosol and tyrosol in extra virgin olive oil after hydrolysis processes
Author(s) -
Mulinacci Nadia,
Giaccherini Catia,
Ieri Francesca,
Innocenti Marzia,
Romani Annalisa,
Vincieri Franco F
Publication year - 2006
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2411
Subject(s) - tyrosol , hydrolysis , chemistry , alkaline hydrolysis , chromatography , high performance liquid chromatography , hydroxytyrosol , oleuropein , organic chemistry , antioxidant , acid hydrolysis , polyphenol
Abstract We describe chemical hydrolytic procedures to evaluate the total amount of tyrosol and hydroxy‐tyrosol free and/or linked to secoiridoidic molecules (acid hydrolysis). At the same time a rapid determination of the lignans in complex minor polar compound (MPC) extracts is proposed (alkaline hydrolysis). High‐performance liquid chromatography/diode array detection (HPLC/DAD) and HPLC/MS were applied as reference methods to evaluate the quantitative results from the hydrolysis experiments. The optimized acid hydrolysis procedures were first applied to an oleuropein standard and then to MPC fractions extracted from several commercial extra virgin olive oils. The results confirm the applicability of the method, consisting in the acid hydrolysis of complex mixtures of secoiridoidic derivatives, to determine the antioxidant potential in terms of MPC. These data can contribute to forecasting the potential ageing resistance of an extra virgin olive oil in terms of antioxidant potency. Finally, alkaline hydrolysis allows confirmation and easy determination of the amount of lignans, especially in those MPC fractions which are particularly complex. Copyright © 2006 Society of Chemical Industry