Modeling Food Fluorescence with PARAFAC

Abstract

Parallel factor analysis (PARAFAC) of food fluorescence has found many applications in food science, such as in non-contact and non-destructive food characterization, the detection of food adulteration, and the authentication of geographical and botanical origins of food products. This Chapter presents a theoretical background of the PARAFAC method and a step-by-step guide for the practical use of PARAFAC to model fluorescence excitation-emission matrices and interpret the results. For this purpose, several examples of its use in applications of food fluorescence are presented. PARAFAC can decompose complex excitation-emission matrices into emission and excitation spectra of individual components that contribute to the fluorescence of the investigated sample. These components originate from fluorophores; for this reason, Sect. 8.2 of this Chapter is devoted to the description of fluorophores present in food products. Finally, an extensive overview of literature reports on the use of PARAFAC for modeling food fluorescence is provided. Emphasis is given on the measured EEM spectral ranges, the components used for the PARAFAC modeling, and the intended research aim. This Chapter also presents the use of second-order calibration of PARAFAC scores for the quantitative determination of concentrations of fluorophores.