On the Presence of Steryl Glucosides in Virgin Olive Oil and their Relationship with other Minor Compounds: Untangling the Skein

Abstract

This work extends previous research regarding the role of (esterified) steryl glucosides -(E)SG-in olive oil. In line with previous research and to contribute to a comprehensive olive oil chemical characterization, we have determined the profile and content of these compounds in different mono-variety virgin olive oils using cholesterol β-D-glucoside (ChSG) as single internal standard. To do this, we have collected 22 types of olive cultivars, extracted the oils by the Abencor® method and applied a formerly developed SPE protocol. We have also determined the corresponding response factors with respect to the internal standard. Additionally, we have analyzed some of the purity and quality parameters included in the Regulations with the aim of understanding their relationship with those sterol derivatives. Results show the feasibility of using ChSG as internal standard, shortening the global time of analysis. They also confirm the suitability of the limits previously established for the presence of ESG in olive oil (0.2 -14.0 mg . kg -1 ), but almost double those for SG (up to 4.77 mg . kg -1 ). Data also indicates the lack of a direct, stoichiometric relationship between some possible substrates (sterols, free fatty acids and related compounds) and the products -(E)SG-. Future lines of research are therefore outlined.Keywords: Esterified Steryl Glucosides (ESG); Minor Compounds; Olive Oil; Purity Parameters; Quality Parameters; Steryl Glucosides (SG) AbbreviationsChSG, cholesterol β-D-glucoside; (E)AvSG, (esterified) Δ5-avenasteryl glucoside; (E)BSSG, (esterified) β-sitosteryl glucoside; (E)CSG, (esterified) campesteryl glucoside; ES, esterified sterols; Raquel B. Gómez-Coca, Rosario Cruz-Hidalgo, Gabriel D. Fernandes, Daniel Barrera-Arellano, Marí a del Carmen Pérez-Camino, and Wenceslao Moreda / American Journal of Agricultural Science and Technology (2015) Vol. 3 No. 1 pp. 24-37 25 ESG, esterified steryl glucosides; (E)SG, (esterified) steryl glucosides -meaning either of the two or both species-; (E)SSG, esterified stigmasteryl