Electrophoretic identification and quantitation of compounds in the polyphenolic fraction of extra-virgin olive oil

Abstract

A capillary zone electrophoresis method has been carried out to determine and quantitate some compounds of the polyphenolic fraction of virgin olive oil which have never previously been determined before using capillary electrophoresis, such as elenolic acid, ligstroside aglycon, oleuropein aglycon, and (+)-pinoresinol. The compounds were identified using standards obtained by semipreparative high-performance liquid chromatography (HPLC). A detailed method optimization was performed to separate the phenolic compounds present in olive oil using a methanol-water extract of Picual extra-virgin olive oil, and different extraction systems were compared (C18-solid phase extraction (SPE), Diol-SPE, Sax-SPE and liquid-liquid extraction). The optimized parameters were 30 mM sodium tetraborate buffer (pH 9.3) at 25 kV with 8 s hydrodynamic injection, and the quantitation was carried out by the use of two reference compounds at two different wavelengths.

Rapid Quantification of the Phenolic Fraction of Spanish Virgin Olive Oils by Capillary Electrophoresis with UV Detection

“…As far as the recoveries of these compounds are concerned using solid-phase extraction, it is important to explain that we have used the protocol described by Gómez-Caravaca et al (21), and we have spiked a refined sunflower oil with an exactly specified dose of a phenolic extract previously obtained. The results are summarized in Table 3.…”

“…To isolate the phenolic fraction, we used SPE with DSC-Diol cartridges; the SPE protocol was carried out with the extraction conditions and amounts of oil that are described in a recent paper of our research group (21).…”

“…In particular, this technique has recently been used for the analysis of phenolic compounds of extra-virgin olive oil (14)(15)(16)(17)(18)(19)(20)(21), olive mill wastewater (22), and alperujo (23).…”

“…Then, in a published paper by our group (21), the number of identified compounds in an electrophoretic profile of an extract of virgin olive oil increased using standards obtained by semipreparative HPLC, although the analysis time in this case was long.…”

Phenolic Molecules in Virgin Olive Oils: a Survey of Their Sensory Properties, Health Effects, Antioxidant Activity and Analytical Methods. An Overview of the Last Decade Alessandra

“…Herein, the publications including CE-UV and CE-MS are summarized (see Tables 4 and 5). Applicative work using a previously method [218] Interesting from a quantitative and applicative point of view [188] 60 g → 2 mL (SPE-Diol [216]) and diluted 1:10…”