Chemometric strategies assessment for the quantitation of dyes using fluorescence spectroscopy

Abstract

Food colourings are additives very common nowadays in the food industry. Its main applications are to give a visual value to the food and to give the costumer an idea about the quality of it. Furthermore, other uses are to recover the colour that some products may lose during the commercialization due to light exposure, temperature changes and humidity. Moreover, food colourings are also used to enhance the natural colours of the food and its appearance or to give an idea about its condition. Even though its advantages, use of food dyes is very restrictive for human consumption. An excessive intake of food colourings may lead to a variety of health issues. Nowadays, those diseases are mainly related to allergies or hyperactivity. For this reason, the use of food dyes must be regulated, and their quantities in edible foods must be controlled. There are plenty of ways to analytically quantify food dyes. Fluorescence spectroscopy is an option to quantify food colourings which has benefits such as its high selectivity and sensibility. The main objective of this project is to take advantage of fluorescence properties to analyse mixtures of different food colourings with different complexity. Afterwards, different multivariate analysis strategies will be tested with the fluorescence data obtained to build models able to quantify different food colorants. Therefore, different chemometric models based on MCR-ALS were built considering the differences between the different fluorescence acquisition modes (single or multiple excitation wavelengths). As a result, the models built with fluorescence emission at a single wavelength using MCR-ALS and calibration constraints seemed to explain the data better than the models built with 3D excitation emission spectra using classical MCR-ALS constraints