Chemometric Discrimination Between Smoked and Non-Smoked Paprika Samples. Quantification of PAHs in Smoked Paprika by Fluorescence-U-PLS/RBL

Abstract

This study presents a strategy for differentiating paprika obtained by means of different drying systems. The differentiation is performed using spectroscopic fluorescence in combination with multivariate analysis. The two groups of samples (smoked or non-smoked paprika) are classified according to the content of some of their fluorescent compounds presented in each group, among which several polycyclic aromatic hydrocarbons (PAHs) are included. These compounds are characteristic in smoked food. The full information of excitation–emission matrices (EEMs) is processed with the aid of unsupervised parallel factor analysis (PARAFAC), PARAFAC supervised by linear discriminant analysis (LDA) and discriminant unfolded partial least squares (DU-PLS). The last algorithm allows an adequate classification of unknown paprika samples. Besides, the quantification of several PAHs in paprika was performed by means of unfolded partial least squares with residual bilinearization (U-PLS/RBL). On this way, three (fluorene, phenantrene, and anthracene) out of the five (fluorene, phenantrene, anthracene, pyrene and chrysene) selected analytes were quantified.