Fluorescence excitation–emission matrix spectroscopy as a tool for determining quality of sparkling wines

Characterization and authentication of Spanish PDO wine vinegars using multidimensional fluorescence and chemometrics

“…According to the literature, the excitation/emission wavelengths of this factor could be related to phenolic compounds, the best known fluorescent molecules naturally present in wine that differ in accordance to the grape variety and the vinegar ageing. This group of compounds includes phenolic acids and phenolic aldehydes, as well as oxidation and Maillard reaction products (present due to browning processes and oxidative mechanisms taking place during ageing and storage), which have shown maximum excitation/emission wavelengths around 330/420 nm (Airado-Rodríguez et al, 2011;Azcarate et al, 2015;Callejón et al, 2012;Dufour et al, 2006;Elcoroaristizabal et al, 2016;Sádecká & Tóthová, 2007). In contrast, in "Condado de Huelva" PDO this F4 presents its excitation and emission maxima around 485/560 nm (λ ex / λ em ), and it could be associated with the aforementioned vitamin B2.…”

“…Some of these chemical compounds are polyphenols, amino acids and vitamins (Airado-Rodríguez, Durán-Merás, Galeano-Díaz, & Wold, 2011), whose presence is related to the wine chemical basis. To handle this complexity, fluorescence multidimensional measurements, such as excitationemission fluorescence spectroscopy, combined with adequate multi-way methods (Andersen & Bro, 2003;Sádecká & Tóthová, 2007) have been proven to be useful for characterization of complex food matrices (Callejón et al, 2012;Christensen, Becker, & Frederiksen, 2005;Elcoroaristizabal et al, 2016;Lenhardt, Bro, Zeković, Dramićanin, & Dramićanin, 2015). Measuring the emission spectra at different excitation wavelengths results into a bi-dimensional Excitation-Emission Matrix (EEM), which contains unique information of each measured sample.…”

“…The information provided by the resolved fluorophores has been successfully applied in food quality control, since it can reveal clearer insights into the relationships between the intrinsic food properties and the quality of the product. For instance, EEM-PARAFAC has been applied for monitoring the changes occurring during the storage and production of different food samples (Christensen, Becker, & Frederiksen, 2005;Elcoroaristizabal et al, 2016) and their characterization (Lenhardt et al, 2015;Tena, Aparicio, & García-González, 2012).…”

“…Figure 2 includes the PARAFAC loadings (excitation and emission spectra) of the extracted factors present in each Spanish PDO vinegar, whose corresponding fluorescence emission and excitation maxima are listed inTable IV(Supplementary Material). The fluorescent loading patterns of the modelled factors can be matched to fluorophores described in the literature(Airado-Rodríguez et al., 2011;Dufour, Letort, Laguet, Lebecque, & Serra, 2006;Elcoroaristizabal et al, 2016). However, it is important to note that vinegar contains a wide variety of naturally occurring fluorescent compounds, being each emission/excitation profiles a sum of related fluorescent molecules and not only to a single one(Airado-Rodríguez et al, 2011).…”

Investigating challenges with scattering and inner filter effects in front‐face fluorescence by PARAFAC

“…In particular, in the field of food science, it has been used to characterize foods that have undergone industrial processes and subjected to different storage conditions or for traceability of protected designation of origin products. [5][6][7][8][9][10][11][12][13][14][15][16][17] In the field of environmental chemistry, the use of PARAFAC for the analysis of untreated samples measured with fluorescence spectroscopy is largely and successfully applied for characterizing organic matter in water systems. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Such good results reported in the literature pave the way for the possibility of extending the use of this approach to reach a deeper understanding of the nature of any fluorophore directly in the sample: the use of frontface fluorescence, combined with three-way analysis of the data, seems an easier and faster choice, which could be applied as an alternative to long and tedious lab procedures in many fields of research.…”