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

• Browning in sparkling wines was assessed by fluorescence EEM spectroscopy-PARAFAC.
• Four component PARAFAC model explained spectral profiles of different sparkling wines.
• The third PARAFAC factor (465/530 nm), A420 and 5-HMF content were highly correlated.
• The pairs 465/530 nm and 280/380 nm are useful to monitor the browning in sparkling wines.

Browning in sparkling wines was assessed by the use of excitation–emission fluorescence spectroscopy combined with PARAllel FACtor analysis (PARAFAC). Four different cava sparkling wines were monitored during an accelerated browning process and subsequently storage. Fluorescence changes observed during the accelerated browning process were monitored and compared with other conventional parameters: absorbance at 420 nm (A420) and the content of 5-hydroxymethyl-2-furfural (5-HMF). A high similarity of the spectral profiles for all sparkling wines analyzed was observed, being explained by a four component PARAFAC model. A high correlation between the third PARAFAC factor (465/530 nm) and the commonly used non-enzymatic browning indicators was observed. The fourth PARAFAC factor (280/380 nm) gives us also information about the browning process following a first order kinetic reaction. Hence, excitation–emission fluorescence spectroscopy, together with PARAFAC, provides a faster alternative for browning monitoring to conventional methods, as well as useful key indicators for quality control.