Development of Rapid Extra Virgin Olive Oil Quality Assessment Procedures Based on Spectroscopic Techniques

Paola Baltazar,Natalia Hernández-Sánchez,Belén Diezma,Lourdes Lleó

doi:10.3390/agronomy10010041

Paola Baltazar, Natalia Hernández-Sánchez + Show 2 more

Open Access

https://doi.org/10.3390/agronomy10010041

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Abstract

The main objective of this study was to evaluate the feasibility of developing multivariate models to estimate physico-chemical characteristics and antioxidant content of extra virgin olive oil from fluorescence spectra obtained at specific excitation wavelengths. Six replicates of each extra virgin olive oil sample were contained in clear glass bottles. Two replicates were subjected to four weeks of natural indirect light; two bottles for two days; and the third couple were kept it in darkness as a control. For each pair, one bottle was used for spectroscopic measurements and the other was sent to an accredited external laboratory to obtain physico-chemical measurements: acidity, peroxide index, K270, K232, total tocopherols, α-tocopherol, β-tocopherol and γ-tocopherol. Fluorescence emission spectra were acquired at different excitation wavelengths: 326 nm, 350 nm and 365 nm and partial least squares regression (PLSR) models were developed. The highest R2 values were found for excitation at 350 nm, reaching almost 0.9 in most of the parameters.

Highlights

The production and consumption of olive oil has increased and extended from the Mediterranean area to other regions of the world
The growing interest in this product, especially in extra virgin olive oil (EVOO), is based on its beneficial properties for health and on its sensory attributes, since it is rich in monounsaturated fatty acids and antioxidant compounds such as polyphenols and tocopherols
Regulations establish the categorization of the olive oil according to numerous physico-chemical characteristics that are analyzed in accredited laboratories, as well as to organoleptic evaluation by accredited tasting panels

Summary

Introduction

The production and consumption of olive oil has increased and extended from the Mediterranean area to other regions of the world. The growing interest in this product, especially in extra virgin olive oil (EVOO), is based on its beneficial properties for health and on its sensory attributes, since it is rich in monounsaturated fatty acids and antioxidant compounds such as polyphenols and tocopherols. In this context, EVOO marketing is more demanding in terms of quality assurance. Regulations establish the categorization of the olive oil according to numerous physico-chemical characteristics that are analyzed in accredited laboratories, as well as to organoleptic evaluation by accredited tasting panels These analyses are usually laborious, slow and expensive

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