Delineation of the structure of soft cheeses at the molecular level by fluorescence spectroscopy - relationship with texture

Tryptophan fluorescence spectra of eight different soft cheeses were record ed directly on cheese samples using front-face fluorescence spectroscopy. D iscriminant ability of the data was investigated by discriminant analysis. A correct classification was observed for 95% and 92% of the calibration an d validation samples, respectively. It was concluded that tryptophan fluore scence spectra enable the identity of individual cheeses to be finger-print ed. Canonical correlation analysis was applied to soft-cheese sensory profi le data and fluorescence spectral collection in order to measure the link b etween the two groups of variables measured on the same samples. The two gr oups of variables were found highly correlated since the squared canonical coefficients for canonical variates 1 and 2 were 0.93 and 0.80, respectivel y. A subset of four cheeses was investigated closely in order to establish a molecular basis of the discrimination. It was shown that molecular level information may be derived from the fluorescence spectra. (C) 2001 Elsevier Science Ltd. All rights reserved.