Original scientific paper
Usefulness of near infrared spectroscopy and chemometrics in screening of the quality of dessert wine Prošek
Irena Budić-Leto
; Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21000 Split, Croatia
Jasenka Gajdoš Kljusurić
orcid.org/0000-0001-6657-7337
; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia
G. Zdunić
; Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21000 Split, Croatia
Iva Tomić-Potrebuješ
; Institute for Adriatic Crops and Karst Reclamation, Put Duilova 11, 21000 Split, Croatia
Mara Banović
; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia
Ž. Kurtanjek
; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia
T. Lovrić
; University of Zagreb, Faculty of Food Technology and Biotechnology, Pierottijeva 6, 10000 Zagreb, Croatia
Abstract
NIRS has been applied for the analysis of dessert wine Prošek produced from dried grapes of Pošip and Plavac mali cv. in a semi-scaled fermentation. It is a fast and non-destructive analytical method that in association with chemometrics is becoming more frequently used technique. NIR spectra were measured and the relative density, alcohol content, dry extract, reducing sugars, pH, total acidity, volatile acidity, ash, free sulphur dioxide and total sulphur dioxide were determined. The range of NIRS used in this paper was 904–1699 nm (i.e. 11062–5886 cm−1) because in this range vibrations of C–H, O–H, S–H and N–H bonds can mainly be observed.
Using the basic principles of multivariate analysis, principal component analysis (PCA), was used to reduce the input matrix in order to look for significant relationships between the NIR spectra and the observed characteristics of wine Prošek. Chemometrics applied here resulted in further discrimination between samples. The main features of the spectra are absorption bands at 1580 and 1670 nm, which are related to the first overtone of the C–H stretch. Absorption bands around 908 nm, present the stretches related to the 3rd C–H overtone and 2nd overtone of the O–H stretch of H2O and ethanol. PC1 and PC2, the first two components, gave the highest level of classification (≈95 %) based on the grape used for wine production as well as on the added yeast.
The potential of NIRS, as a non-destructive method, is screening of basic parameters that are usually determined during the winemaking and ageing of wine. The results of investigations confirm that NIRS combined with chemometric analysis is a promising tool for quality control and for on-line application in the control of the final product, Prošek.
Keywords
dessert wine; quality parameters; NIRS; chemometrics
Hrčak ID:
76157
URI
Publication date:
30.12.2011.
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