Pilot-plant scale extraction of phenolic compounds from grape canes: Comprehensive characterization by LC-ESI-LTQ-Orbitrap-MS

Grape canes, also named vine shoots, are well-known viticultural byproducts containing high levels of phenolic compounds, which are associated with a broad range of health benefits. In this work, grape canes (Vitis vinifera cv. Pinot noir) were extracted in a 750 L pilot-plant reactor under the following conditions: temperature 80 degrees C, time 100 min, solid/liquid ratio 1:10. The comprehensive characterization of grape cane phenolic compounds was performed by liquid chromatography coupled to high-resolution/accurate mass measurement LTQ-Orbitrap mass spectrometry. A total of 44 compounds were identified and, 26 of them also quantified, consisting of phenolic acids and aldehydes (17), flavonoids (12), and stilbenoids (15). The most abundant class of phenolics were stilbenoids, among which (E)-epsilon-viniferin predominated. The phenolic profile of grape canes obtained using pilot plant extraction differed significantly from the results of laboratory-scale studies obtained previously. Additionally, we observed a high antioxidant capacity of grape cane pilot-plant extract measured by the radical antioxidant scavenging potential (ABTS(.+)) (2209 +/- 125 mu mol TE/g DW) and oxygen radical absorbance capacity using fluorescein (ORAC-FL) (4612 +/- 155 mu mol TE/g DW). Grape cane pilot-plant extract for their phenolic profile may be used as a by-product for the development of novel nutraceutical and pharmaceutical products, improving the value and the sustainability of these residues.

Automated summary

Grape canes, known as vine shoots, contain high levels of phenolic compounds that offer a range of health benefits. Extracts from grape canes obtained using a pilot-plant reactor were found to have a different phenolic profile compared to previous laboratory-scale studies. The extracts showed high antioxidant capacity and may potentially be used in the development of novel nutraceutical and pharmaceutical products, increasing the value and sustainability of these residues.