Rapid Analytical Method to Characterize the Freshness of Olive Oils Using Fluorescence Spectroscopy and Chemometric Algorithms

Abstract

<jats:p>One of the most important issues in the field of quality assurance of olive oils is the detection of the freshness of olive oil. In this study, 400 nm laser-induced fluorescence spectroscopy was used with supervised and unsupervised multivariate analysis methods to develop a rapid method able to discriminate between freshly produced olive oils and oil that has been stored for a period of time ranging from 12 to 24 months. The fluorescence spectral data were firstly processed by the PCA. This method shows strong discrimination of the three oil classes using the first three components which present 96% of the total variability of the initial data, and then supervised classification models were constructed using the discriminant partial least square regression PLS-DA, support vector machine SVM, and linear discriminant analysis LDA. These methods show a high capacity in the classification of the three classes of olive oil. The validation of these classification models by external samples shows a high capacity of classification of the samples in their class with an accuracy of 100%. This study demonstrated the feasibility of the fluorescence spectroscopy fingerprint (routine technique) for the classification of olive oils according to their freshness and storage time.</jats:p>

Near UV-Vis and NMR Spectroscopic Methods for Rapid Screening of Antioxidant Molecules in Extra-Virgin Olive Oil

“…Other spectroscopies applied to the study of olive oil are related to the absorption of UV-Vi light (UV-Vis absorption spectroscopy) and to fluorescence emission in the UV-Vis region (fluorescence spectroscopy). This last technique was only recently used to investigate the quality and authenticity of olive oil, mainly focusing on the chlorophyll contents in fresh oils versus not-fresh oils [ 20 ] and to the emission spectral profiles due to the polyphenols present in olive oil [ 21 ]. UV-Vis absorption spectroscopy is a technique able to detect with relatively high sensitivity single pigment contents in the visible range (from ~400 nm to ~800 nm) and other compounds present in olive oil, such as polyphenols, peroxides and other fatty acid derivatives due to the oxidation of olive oils, in the UV range (from ~230 nm to ~400 nm).…”

Exploration of Spanish Olive Oil Quality with a Miniaturized Low-Cost Fluorescence Sensor and Machine Learning Techniques

“…Unsurprisingly, the results obtained with SVM are poorer than those obtained with the other methods as typically with those algorithms pre-processing is a key part of the analysis. In fact, in previous work, SVM was applied after pre-processing the data, for example with PCA, to obtain a good accuracy [ 54 ]. PCA with LDA was studied using an increasing number of PCA components: 2, 3, 4, 5, 10, 15, 20, 25, and 30.…”

Development of Fast Analytical Method for the Detection and Quantification of Honey Adulteration Using Vibrational Spectroscopy and Chemometrics Tools

“…The PCs describe, in descending order, the largest variations between characteristics, and because they are calculated to be orthogonal to each other, each PC can be interpreted independently. This gives an overview of the data structure by revealing the relationships between objects and the detection of deviant features [ 17 , 18 ].…”