The phenolic compounds, organic acids and the antioxidant activity were determined for grape juice samples from new Brazilian varieties grown in the Sub-middle São Francisco Valley in the Northeast Region of Brazil. The results showed that the Brazilian grape juices have high antioxidant activity, which was significantly correlated with the phenolic compounds catechin, epicatechin gallate, procyanidin B1, rutin, gallic acid, caffeic acid, p-coumaric acid, pelargonidin-3-glucoside, cyanidin-3-glucoside, cyaniding-3,5-diglucoside and delphinidin-3-glucoside. The produced juice samples showed higher concentrations of trans-resveratrol than those observed in juices made from different varieties of grapes from traditional growing regions. Organic acids concentrations were similar to those of juices produced from other classical varieties. It was demonstrated that it is possible to prepare juices from grapes of new varieties grown in the Northeast of Brazil containing a high content of bioactive compounds and typical characteristics of the tropical viticulture practised in the Sub-middle São Francisco Valley.

Grapes are rich in polyphenols with biologically active properties. Although the bioactive potential of grape constituents are frequently reported, the effects of Brazilian Vitis labrusca L. grape juices ingestion have not been demonstrated in humans. This study identified the phenolic and elemental composition of red and white grape juices and the effect of organic and conventional red grape juice consumption on lipid peroxidation in healthy individuals. Concentrations of anthocyanins, flavanols and phenolic acids and the in vitro antioxidant activity were significantly higher in the organic juice. The macro-elements K, Ca, Na and Mg were the most abundant minerals in all juices. The acute consumption of red grape juices promoted significant decrease of lipid peroxides in serum and TBARS levels in plasma. It is concluded that red V. labrusca L. grape juices produced in Southern Brazil showed lipid peroxidation inhibition abilities in healthy subjects, regardless of the cultivation system.

The effect of maceration process on the profile of phenolic compounds, organic acids composition and antioxidant activity of grape juices from new varieties of Vitis labrusca L. obtained in industrial scale was investigated. The extraction process presented a high yield without pressing the grapes. The use of a commercial pectinase resulted in an increase on extraction yield and procyanidins B1 and B2 concentrations and a decrease on turbidity and concentration of catechins. The combination of 60 °C and 3.0 mL 100 kg(-1) of enzyme resulted in the highest extraction of phenolic compounds, reducing the content of acetic acid. The juices presented high antioxidant activity, related to the great concentration of malvidin, cyanidin, catechin and caffeic, cinnamic and gallic acids. Among the bioactive compounds, the juices presented high concentration of procyanidin B1, caffeic acid and trans-resveratrol, with higher levels compared to those reported in the literature.

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The bioactivity of trans-Resveratrol (RSV), an important wine polyphenol, and of its 53 metabolites was investigated in a more relevant setup comprising an in vitro co-culture cell 54 model that combines intestinal absorption and conjugation with changes in endothelial 55 function, which is primarily affected in cardiovascular diseases. Caco-2 and endothelial 56 EA.hy926 cells were grown in a co-culture and Caco-2 cells were treated with RSV, in the 57 co-culture and in two different sequential setups, for 4 h and 24 h. Transported metabolites 58 were investigated by UPLC-MS/MS E and the effects on NO production, ROS inhibition and 59 secretion of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8) and intercellular 60 adhesion molecule-1 (ICAM-1) were evaluated in TNF-α-activated and non-activated 61 endothelial cells. RSV and four conjugated metabolites, two sulfates and two glucuronides, 62 were identified after intestinal transport. In both co-culture and sequential systems, RSV at 63 20 µM strongly induced NO production. Changes in ROS and NO levels demonstrated a 64 clear effect of crosstalk between cells in the co-culture. The secretion of proinflammatory 65 cytokines and VEGF was largely increased by treatment with TNF-α (inflammatory 66 condition). The polyphenol intervention significantly reduced the levels of VEGF, ROS, IL-8 67 and ICAM-1, with a more pronounced effect in TNF-α-activated endothelial cells. In 68 conclusion, RSV and its metabolites showed accentuated bioactivity on TNF-α-induced 69 inflammation and the metabolism of endothelial cells as a biological target was not only 70 influenced by these phenolics, but also by the communication between distinct cell lines, 71 showing a new perspective for investigations on polyphenol intervention and its biological 72 outcomes.

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