Fluoresence Spectra From Vegetable Oils Using Violet And Blue Ld/Led Exitation And An Optical Fiber Spectrometer

Abstract

In this article the possibility to detect adulteration of costly olive oils with cheaper vegetable oils using fluorescence spectroscopy is studied. Total luminescence spectra were recorded by measuring the emission spectra in the range 350 nm to 720 nm for excitation wavelengths from 375 nm to 450 nm. Fluorescence spectra of 12 types of olive oil samples were studied. Ten of the olive oil types were purchased locally, while two (samples 1 and 4) were obtained directly from Greek olive oil producers. Analysis of the fatty acid and the tocopherol contents has been performed. Two of the samples exhibit the content of sunflower oils, two are admixtures of sunflower and olive oils, while the remaining eight samples are natural olive oils. The samples show differences in their fluorescence spectra. The latter fact shows that fluorescence spectroscopy can be used for the quick identification of possible adulterations of olive oil, although a more detailed gas chromatographic analysis is needed for the exact quantitative determination of the content of the adulterant.

Two- and Three-Dimensional Spectrofluorimetric Qualitative Analysis of Selected Vegetable Oils for Biomedical Applications

“…In fact, these are the same correlative spectra in 2D (color) and 3D (peaks), showing complementary information. Since the total fluorescence spectra of the oils show the characteristic bands of vegetable oils, the short-wavelength band in the excitation range of 270-310 nm and the emission range of 300-360 nm, which is presented in most samples of oils (A, B, C, G), could be attributed to the tocopherol emission, as reported in the literature [39]. From the recorded intensity, it could be stated that tocopherol is one of the main ingredients.…”

Improvement in Thermochromic Offset Print UV Stability by Applying PCL Nanocomposite Coatings

“…As the thermochromic inks used in the study were vegetable-oil-based, their fluorescent response was expected due to their composition of mainly chlorophylls, parinaric acid, and vitamin E [ 49 ]. Different oils show different exhibition peaks; sunflower oil exhibits fluorescence peaks in the 430 to 520 nm region [ 50 ], extra virgin olive oil between 500 and 720 nm [ 51 , 52 ], rapeseed oil with characteristic spectra from 300 to 500 and from 630 to 730 nm [ 49 ].…”

Intrinsic Fluorescence Markers for Food Characteristics, Shelf Life, and Safety Estimation: Advanced Analytical Approach

“…Based on the spectral and chemical analysis, certain samples were found to be mixtures of sunflower and olive oils, while some of them were natural olive oils. Thus, fluorescence spectroscopy has been shown to be suitable for the rapid detection of olive oil adulterations [ 79 ].…”