Monitoring of mild heat treatment of camel milk by front-face fluorescence spectroscopy
Résumé
The potentiality of the front-face fluorescence spectroscopy coupled with chemometric tools to characterize changes in camel milk following thermal treatments in the 55–75 °C temperature range from 0.5 min up to 30 min was studied. Nicotinamide adenine dinucleotide (NADH), fluorescent Maillard reaction products (FMRP) and vitamin A fluorescence spectra were collected on camel milk samples. Using principal component analysis (PCA), the vitamin A spectra allowed some discrimination between milk samples according to heat treatment intensity and holding time. The best results was obtained by applying common components and specific weights analysis (CCSWA) to the three spectral data sets, since a clear differentiation between camel milk samples preheated at 70 and 75 °C from the others was achieved. Apparent activation energy of camel milk determined from NADH, FMRP and vitamin A spectra was of 85.1, 84.2 and 47.3 kJ mol−1, respectively. The spectral patterns of the CCSWA model enabled us to get information about the molecular changes occurring in camel milk fluorophores during heat treatment.