Phenolic Content and Antioxidant Capacity of Infusions of Vitis tiliifolia (Humb & Bonpl. Ex Schult.) Leaves

The antioxidant capacity and polyphenol contents in leaves of Vitis tiliifolia are unknown. Leaves from four accessions of Vitis tiliifolia grown ex situ in the collection of the Universidad Autónoma Chapingo, Veracruz - Mexico, were collected in Autumn (۲۰۱۵) and Spring (۲۰۱۶), dehydrated and used to make water infusions at ۸۰oC for ۵ minutes. The four accessions were propagated from wild grapevines which grow in Huatusco, Atlahuilco, Cosautlan and Ixtaczoquitlan. The aqueous infusions were analyzed to evaluate the antioxidant capacity by application of ۲,۲-DiPhenyl-۱-PicrilHydrazyl (DPPH), and the total phenolic compounds (total reducing power) were determined spectrophotometrically by the Folin-Ciocalteu method. The polyphenols identification and quantification were determined using an ultrahigh resolution liquid chromatograph. Fourteen compounds, including trans-resveratrol, quercetin and rutin were identified. The infusions obtained from leaves of Huatusco and Ixtaczoquitlan accessions had the highest contents of total phenols. The infusions from leaves of Cosautlan and Ixtaczoquitlan accessions showed the highest antioxidant activities. The results indicate that the Vitis tiliifolia leaves in infusions are a rich source of bioactive compounds. This is the first time that the phenolics content and the antioxidant capacity of leaf infusions of Vitis tiliiflolia leaves are reported. As a large variability was found in the compounds of the different accessions, a selection of the genotypes with the most suitable composition of the leaves for their use in infusions and subsequent cultivation could represent a way for the valorization of Vitis tiliifolia and to diversify the agricultural productions in tropical areas.

Keywords:

Grapevine leaves , Mesoamerican Vitis , Polyphenols , Trans-resveratrol.