Distinguishing organic wines from normal wines on the basis of concentrations of phenolic compounds and spectral data

European Food Research and Technology v.212 i.3 (2001) pp 390-394 20feb01

Abstract

Soili Tinttunen (1)(2), P. Lehtonen (1)

(1) Alcohol Control Laboratory, Alko Inc., P.O. Box 279, 01301 Vantaa, Finland e-mail: Pekka.Lehtonen@Alko.fi
(2) Laboratory of Analytical Chemistry, University of Helsinki, P.O. Box 55, 00014 Helsinki, Finland

Received: 19 May 2000 / Revised: 26 July 2000

Abstract This study was undertaken to determine whether it is possible to distinguish organic wines from normal wines on the basis of chemical composition and spectral data. A total of 58 wine samples including organic and normal red and white wines from France and Germany were analysed. The concentrations of several phenolic compounds, including trans-resveratrol, were determined using reversed-phase high-performance liquid chromatography with both diode array and coulometric electrode array detection. In addition, total phenols, total acids, pH and SO₂ were determined. The ultraviolet-visible (UV-vis) spectra of wines were measured, and the absorbances at four different wavelengths were determined.

The data were processed statistically using principal component analysis (PCA). Despite several different combinations of variables, separation of white wines was only achieved according to geographical origin. PCA differentiated well between organic Burgundy red wines and normal Burgundy wines. The separation was based on the concentrations of caffeic and gallic acids, total phenol content and the absorbance ratios A₂₅₄/A₂₇₆, A₂₇₆/A₃₂₀ and A₃₂₀/A₅₂₀. PCA was unable to differentiate organic white wines from corresponding normal wines.

The mean trans-resveratrol concentrations of 16 organic red wines and 16 normal red wines were 5.6 mg/l and 2.9 mg/l, respectively. The highest concentration, 14,5 mg/l, was found in an organic red wine from the Loire district in France.

Keywords Organic wines · Phenolic compounds · Antioxidants · Resveratrol · Principal component analysis (PCA)

source: http://link.springer-ny.com/link/service/journals/00217/tocs/t1212003.htm 03mar01