Red grapes contain elevated amounts of antioxidant compounds (polyphenols) that may potentially prevent cell aging, cardiovascular disease and oxidation-related disorders. Since functional drinks are presently one of the most dynamic sectors of the market, the present work was aimed at evaluating the possible antioxidant effect of an experimental grape juice in terms of urinary 6-sulfatoxymelatonin (aMT6-s) and total antioxidant capacity in young (20 ± 10 yr-old), middle-aged (45 ± 10 yr-old) and elderly (75 ± 10 yr-old) individuals. Grapes (Vitis vinifera cv. Tempranillo) were de-stemmed, racked and pressed. The juice was subsequently stabilized by high hydrostatic pressure (HHP). Participants consumed 200 mL of grape juice twice a day (as the lunch and dinner desserts) for 5 days. First-void morning urines were collected before treatment (basal values), the day immediately after the last ingestion of juice (assay), and one day afterwards (post-assay). aMT6-s and total antioxidant capacity were quantified using commercial ELISA and colorimetric assay kits, respectively. The intake of grape juice cv. Tempranillo induced a significant increase of urinary aMT6-s and total antioxidant capacity in the three groups of age analyzed as compared to their corresponding basal and post-assay values. These functional/nutraceutical properties may be of interest for a prospective commercialization of the grape juice. The novel technology used for juice stabilization may be suitable for introducing into the market a product with high sensory and nutritional quality, as it has been shown in this study.

The experiment was carried out in a semi-arid terroir of western Spain, Badajoz, to determine the effects of perflowering defoliation on the qualitative and quantitative composition of phenolic compounds in the grape-skins of Tempranillo grapevines. Control vines (C) were compared with defoliation carried out before flowering (ED) in seasons 2009 to 2010. A total of 42 phenolic compounds were identified and quantified in the grape skins including anthocyanins, flavonols, and hydroxycinnamic acids, both as simple and as conjugated molecules, and also flavanols (cathechin and epi-cathechin and the flavanol dimmers B1, B2 and B3). ED treatment did not significantly affect concentration of total anthocyanidins with respect to the control, non-defoliated vines, although in 2009 3-O-acylated monoglucosides and p-coumaroylglucoside forms were increased by prebloom leaf removal. A tendency for the amount of total flavanols to increase due to defoliation treatment was observed but was not significant. Also leaf removal increased concentration of flavonols (glycosides of myricetin, quercetin, kaempherol and isorhamnetin) as well as hydroxycinnamic acids and stilbenes in different ways depending on season. Preflowering leaf removal may contribute to increase concentration of compounds with the ability to form complexes with anthocyanins (copigments), and is able to improving wine color stability.

A scarce amount of knowledge about the use of Colombian berry (CB) in meat products is available in the literature. This work studies the impact of the addition of CB extracts (CBE) on pork patties at three different concentrations in the range 250–750 mg/kg. CBE were characterized in terms of their polyphenolic profile and antioxidant activity [1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, half maximal inhibitory antioxidant concentration (IC₅₀), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP) and oxygen radical absorbance capacity (ORAC) tests)]. After pork patties elaboration, instrumental and sensorial colour, as well as lipid oxidation measured as thiobarbituric acid reactive substances assay (TBARS) values, were evaluated for 10 days of refrigerated storage in a modified atmosphere (80% O₂–20% CO₂). The total anthocyanin composition represented 35% of the polyphenolic substances of the CBE, highlighting high contents in cyanidin derivatives. Additionally, other flavonoids (quercetin and kaempferol compounds) and phenolics acids, substances positively related to antioxidant activity, were identified and quantified. In addition, the incorporation of CBE resulted in improvements in colour and lipid stability of pork patties, especially for the highest concentration used. Our findings demonstrated that CBE could be added to pork patties without impairing their sensorial profile. Overall, our results indicate that the use of CBE as a source of natural antioxidant, natural colourant, or even as a functional ingredient could be promising, but more studies are necessary to confirm it.