Content of trans-resveratrol, trans-ε-viniferin and trans-δ-viniferin in young spring grapevine canes - the influence of samples drying

Abstract

The main objective was to study the effect of sample preparation on the content of trans-resveratrol, trans-ε-viniferin and trans-δ-viniferin in young spring grapevine canes. The samples of six varieties of Vitis vinifera L. ('Hibernal', 'Malverina', 'Kolor', 'Fioletovij Augustovskij', 'Grüner Veltliner' and 'Blaufränkisch') were either lyophilised or slow dried at room temperature (three months), extracted and analysed by HPLC using DAD and FLD detectors and by LC-MS. The presence of trans-δ-viniferin was confirmed by comparison with trans-δ-viniferin prepared by dimerization of trans-resveratrol using laccase and its structure was verified by LC-NMR. The slow drying of the samples at room temperature enables the synthesis of a significant amount of stilbenes in all the studied varieties of V. vinifera canes resulting in a higher stilbene content compared to the lyophilised samples. The results of this study show the importance of the method of drying the cane sample before the extraction and analysis.

Keywords

• viniferins
• vitis vinifera
• grapevine cane
• lyophilization
• room temperature drying
• lc-ms