abstract
- Grapevine leaves are an abundant sub-product of vineyards which is devalued in many regions. The objective of this work is to study the antioxidant activity and phytochemical composition of ten grapevine leaf varieties (four red varieties: Tinta Amarela, Tinta Roriz, Touriga Franca, and Touriga Nacional; and six white varieties: Côdega do Larinho, Fernão Pires, Gouveio, Malvasia Fina, Rabigato, and Viosinho) to select varieties to be used as food ingredients. White grapevine leaves revealed higher antioxidant potential. Malvasia Fina reported better antioxidant properties contrasting with Touriga Franca. Phenolic content varied between 112 and 150 mg GAE g -1 of extract (gallic acid equivalents), hydroxycinnamic acid derivatives and flavonols varied between 76 and 108 mg CAE g -1 of extract (caffeic acid equivalents) and 39 and 54 mg QE g -1 of extract (quercetin equivalents). Malvasia Fina is a good candidate for culinary treatment due to its antioxidant properties and composition in bioactive compounds.