Development and Validation of an Analytical Method for Total Polyphenols Quantification in Extra Virgin Olive Oils

Phenolic compounds in olive oil are considered interesting, both for their effect on human wellness and for their role in the shelf life of olive oils. Many methods have been suggested for quantitative analysis of phenolic compounds in extra virgin olive oil, which determine that results are not always comparable; therefore, it is necessary to have simple, inexpensive, robust, and validated methods for official routine analyses. In this work, solid phase extraction (SPE) was carried out to isolate polyphenols from olive oil and the traditional colorimetric assay (Folin-Ciocalteu method) was used to quantify them. SPE/colorimetric method was validated for total polyphenols official determinations in extra virgin oils. The proposed method was robust, precise, and accurate. Polyphenol recovery was excellent >= 95% in 100-500 ppm measuring range.