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Use of chemometric analysis of NIRS data and antioxidant capacity during the production of dessert wine Prošek from cv. Pošip

Near infrared spectroscopy (NIRS) is a fast and non-destructive analytical method. In association with chemometric modelling, it becomes a powerful tool for application in food industry. In this work was applied for analysis of dessert wine Prošek produced by semi scaled fermentation from dried grapes of cv. Pošip. Samples of raw material and dessert wine Prošek during different stages of production were analysed. NIR spectrums and the antioxidant capacity of the samples beginning from the grape must till the Prošek aged for 2 years were observed. In this paper was used the range of NIR (899–1699 nm, respectively 8495–4495 cm−1) mainly observing vibrations of C–H, O–H, S–H and N–H bonds. In the evaluation of antioxidative capacity of the samples, the Briggs−Rauscher reaction was used as a method based on the inhibitory effects of antioxidants, which is applied near the pH of the fluids in the stomach (pH ≈2). The model allows further discrimination between samples according to the fermentation stages and maturity of the wine. The main features of the spectra are absorption bands at 1610 and 1670 nm which are related to the first overtone of the C–H stretch and 917 nm which are related to the 3rd C–H overtone and 2nd overtone of the O–H stretch of H2O and a combination of stretch and determination of the O–H group in H2O and ethanol, respectively. PC1 and PC2, the first two components, gave the highest level of classification (96%) based on the wine ageing stage and the content of antioxidant components. NIR, as a non-destructive method, has shown the potential for determining antioxidative capacity in must and dessert wine. This paper has presented that NIRS with chemometric analysis is a useful tool for quality control and on-line applications. NIRS can be used qualitatively to detect, to identify, and to qualify raw materials-grape and to control final products, Prošek.

dessert wine; antioxidant activity; BR reaction; NIRs; chemometrics

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