abstract
Substantial amounts of vine wastes are produced during vineyard management, and the chemical profiling of high-value lipophilic phytochemicals is becoming crucial in order to find a complementary route towards their integrated valorisation. The prospection of bioactive phytochemicals from unripe grape, vine shoot, vine cane, stalk and leaf dichloromethane extracts was carried out by gas chromatography-mass spectrometry (GC-MS), analysing samples from a mixture of four red Vitis vinifera L. varieties (Baga, Aragonez, agua Santa and Shiraz), collected at Bairrada Appellation, as a representative case study of typical multi-variety Portuguese vineyards. Vine wastes showed distinct amounts of lipophilic extract, ranging from 0.68% (vine canes) to 13.35% (vine leaves) at dry weight (dw). Thirty-three components were identified, including fatty acids and alcohols, sterols and triterpenoids accounting for amounts from 118.9 mg/100 g dw to 1512.0 mg/100 g dw. The integrated study revealed that unripe grape, stalk and leaf dichloromethane extracts stood out as possible sources of triterpenic compounds (103.2 to 653.5 mg/100 g dw), with lupeol, ursolic and oleanolic acids prevailing. Leaf extract is also reported as an undervalued source of alpha -tocopherol, as the major component detected in this matrix (300.5 mg/100 g dw). These exploratory results are a relevant contribution for the exploitation of undervalued vine residues as a source of health-promoting components with the potential to be used as supplements or nutraceutical ingredients.
keywords
SUPERCRITICAL-FLUID EXTRACTION; GRAPE STALKS; CO2 EXTRACTION; OUTER BARKS; FATTY-ACIDS; L.; ANTIOXIDANT; COMPONENTS; FRACTIONS; RESIDUES
subject category
Biochemistry & Molecular Biology; Chemistry
authors
Salvador, AC; Simoes, MMQ; Silva, AMS; Santos, SAO; Rocha, SM; Silvestre, AJD
our authors
Armando Jorge Domingues Silvestre
Full professor
Sónia Andreia Oliveira Santos
Assistant Researcheracknowledgements
Thanks are due to FCT/MEC for the financial support to the QOPNA research Unit (FCT UID/QUI/00062/2019) and CICECO-Aveiro Institute of Materials (FCT Ref. UID/CTM/50011/2019), through national funds and where applicable co-financed by the FEDER, within the PT2020 Partnership Agreement. A. Salvador and S.A.O. Santos thank the AgroForWealth: Biorefining of agricultural and forest by-products and wastes: integrated strategic for valorisation of resources towards society wealth and sustainability project (CENTRO-01-0145-FEDER-000001), funded by Centro2020, through FEDER and PT2020 for the post-doctoral grant and contract, respectively.