Rapid detection of volatile compounds in apple wines using FT-NIR spectroscopy

The purpose of this work was to study the possibility and ability of NIR spectroscopy to determine the volatile compounds in apple wines. To achieve this, seventy-two samples were scanned using NIR transmission spectroscopy. The volatile compounds were analyzed using HS-SPME-GC-MS. Partial least square (PLS) regression with full cross-validation was applied to develop the calibration models. The calibration results using 42 apple wine samples had a coefficient of determination in full cross validation (R-cv(2)) between 0.8916 for hexanol and 0.8278 for 3,4,5-trimethy1-4-heptanol. The predictive ability of the models was further confirmed by external validation procedure with an independent sample set which did not belong to the calibration group. The resulting values of R-p(2), ranged from 0.9184 for ethyl hexanoate to 0.8811 for 2-phenethanol and 3,4,5-trimethyl-4-heptanol. The residual predictive deviation (RPD) obtained was higher than 2.9 in all the compounds. The results demonstrate that near infrared spectroscopy can be used as a rapid tool to determine the volatile compounds in apple wines. (C) 2015 Elsevier Ltd. All rights reserved.