Application of synchronous fluorescence spectroscopy for the determination of some chemical parameters in PDO French blue cheeses

The present study was aimed at investigating the potential of using synchronous fluorescence spectroscopy (SFS) coupled with multivariate statistical analyses for the determination of some chemical parameters (pH, fat, dry matter, protein and soluble nitrogen) of French blue-veined cheeses belonging to four brands (FA-Fourme d’Ambert, FM-Fourme de Montbrison, BA-Bleu d’Auvergne and BC-Bleu des Causses). Three partial least square regression models with leave-one-out cross-validation technique were considered in the present study. The first one including the “Fourme cheeses” (FA and FM), the second one including the “Blue cheeses” (BA and BC) and the last one including the 4 Blue-veined cheeses (FA, FM, BA and BC). The models qualities were investigated principally by the R2 (coefficient of determination) and the RPD (ratio of standard deviation to root-mean-square error of cross-validation) factors. The results showed that SFS succeeded to predict ash and protein in Blue (ash: R2 = 0.90, RPD = 3.17; protein R2 = 0.80, RPD = 2.24) or Fourme cheeses (ash: R2 = 0.81, RPD = 2.29; protein R2 = 0.81, RPD = 2.26) when considered individually, while SFS failed to predict all the physicochemical parameters when the two groups were analyzed jointly.