APPLICATION OF MULTIVARIATE CALIBRATION TO THE SIMULTANEOUS ROUTINE DETERMINATION OF ETHANOL, GLYCEROL, FRUCTOSE, GLUCOSE AND TOTAL RESIDUAL SUGARS IN BOTRYTIZED-GRAPE SWEET WINES BY MEANS OF NEAR-INFRARED REFLECTANCE SPECTROSCOPY

The simultaneous determination of ethanol, glycerol, fructose, glucose and residual sugars in botrytized-grape sweet white wines was perform ed by means of near-infrared reflectance using 19 interference filters and a partial least squares (PLS) model in latent variables as a mult ivariate calibration technique. The results were compared with those o btained using other multivariate calibration techniques, such as MLR, SWR and PCR, by means of a validation set of samples with known compos itions. Ethanol, fructose and residual sugars were well predicted by a ll the multivariate techniques. Glycerol and glucose showed the highes t prediction residuals. The technique may be of practical interest in the routine analysis of these types of wines with low cost in terms of samples, time and personnel.