Chemical Characterization of Wine Vinegars Belonging to the Vinagre de Montilla-Moriles Protected Designation of Origin, Using Near-Infrared Spectroscopy

Abstract

Spanish wine vinegars belonging to Vinagre de Montilla-Moriles protected designation of origin (PDO) must satisfy some chemical characteristics. These characteristics are mainly responsible of their high and exceptional quality. This study assessed the potential of near infrared spectroscopy (NIRS) as a non-destructive technology for characterizing wine vinegars belonging to this PDO. A total of 107 samples were used to predict major chemical quality parameters (volumic mass, reducing sugars, total acidity and pH) using a scanning monochromator (spectral range 400-2500 nm) with the spinning module, working in transflectance mode. The models developed showed values for the coefficient of regression for cross-validation between 0.95 and 0.99 for volumic mass, reducing sugars and total acidity. Therefore, the results confirm that NIRS technology combined with linear regression strategies such as the modified partial least squares (MPLS) regression can indeed respond to the needs of the vinegars cellars and help them to measure the commonest chemical quality parameters of wine vinegars belonging to Vinagre de Montilla-Moriles (PDO), especially in the case of vinegars with different sugar contents (dry, semi-sweet, sweet and balsamic). However, the number of samples as well as their variability should be increased in order to obtain more robust models.