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Gomez-Alonso S.,University of Castilla - La Mancha | Blanco-Vega D.,University of Castilla - La Mancha | Gomez M.V.,Fundacion Parque Cientifico y Tecnologico de Albacete | Gomez M.V.,University of Castilla - La Mancha | Hermosin-Gutierrez I.,University of Castilla - La Mancha
Journal of Agricultural and Food Chemistry | Year: 2012

Grape anthocyanins reacted with diacetyl, a secondary metabolite of microorganisms involved in winemaking, to form 10-Acetyl-pyranoanthocyanins, a type of anthocyanin-derived pigment similar to other vitisin-type pyranoanthocyanins found in red wines. The structures of 10-Acetyl- pyranomalvidin-3-β-O-glucoside and 10-Acetyl-pyranopeonidin-3-β-O- glucoside were confirmed by spectroscopic methods (UV-vis, MS/MS, and NMR) after their synthesis and isolation. In contrast to other vitisin-type pyranoanthocyanins, the newly described 10-Acetyl-pyranoanthocyanins exhibited differentiated color-related properties. They showed an important tendency to occur as colorless hemiacetals at C-10 under wine pH conditions, while co-occurrence of flavylium cation and quinoidal base yielded a broad visible absorbance band around 510-520 nm. Moreover, they easily reacted with bisulfite in acidic aqueous solution (pH 2.0), but the expected bleaching was not observed. Bisulfite bonded to the carbonyl of 10-Acetyl substituent instead of the expected C-10 position of the pyranoanthocyanin core, thus giving rise to a red pigment hypsochromically shifted toward orangish nuances (maximum absorbances at 487-491 nm). © 2012 American Chemical Society. Source


Barcia M.T.,City University of Sao Paulo | Pertuzatti P.B.,City University of Sao Paulo | Gomez-Alonso S.,Fundacion Parque Cientifico y Tecnologico de Albacete | Gomez-Alonso S.,University of Castilla - La Mancha | And 2 more authors.
Food Chemistry | Year: 2014

The phenolic composition of grapes and winemaking by-products (skins from grape marc, and lees) from Brazilian hybrid cultivars BRS Violeta (red) and BRS Lorena (white) was studied. Two vintages, five classes of phenolic compounds, and recovery yields using three dehydration techniques were considered: oven-drying at 50 °C (D50); spray-drying (SD); and freeze-drying (FD). Recovery yields were higher using FD, although less expensive SD was a good alternative for Violeta lees. D50 caused great recovery reduction in Violeta but yielded similar results for Lorena. Violeta winemaking by-products were excellent sources of anthocyanins (mainly non-acylated and p-coumaroylated diglucosides), flavonols (mainly myricetin-based) and hydroxycinnamic derivatives (mainly caffeic-based). Lorena winemaking by-products contained lesser amounts of phenolic compounds, around a tenth of the values found in Violeta grapes for flavonols (mainly quercetin-based), hydroxycinnamic derivatives (mainly caffeic-based) and condensed tannins. Lorena cultivar contained small amounts of trans-resveratrol and its 3-glucoside, which were missing in Violeta cultivar. © 2014 Elsevier Ltd. All rights reserved. Source


Barcia M.T.,University of Campinas | Pertuzatti P.B.,University of Campinas | Rodrigues D.,University of Campinas | Gomez-Alonso S.,Fundacion Parque Cientifico y Tecnologico de Albacete | And 3 more authors.
Food Research International | Year: 2014

The content of low molecular weight phenolic compounds present in winemaking by-products (skins from grape marc and wine lees) of red wine made from the Vitis vinifera grape cultivars Cabernet Sauvignon and Cabernet Franc in the state of São Paulo (Brazil) has been examined. The study was extended to two consecutive years and showed that winemaking by-products still contained high concentrations of interesting functional and bioactive phenolic compounds. In addition to original grape phenolics, the winemaking by-products contained new phenolics originated by the action of enzymatic (yeast mediated) and chemical reactions during winemaking, including formation of anthocyanin-derived pigments and hydrolysis products from flavonol glycosides and tartaric esters of hydroxycinnamic acids. A total of 19 anthocyanins, 9 pyranoanthocyanins, 18 flavonols, 7 hydroxycinnamic acid derivatives, and 3 resveratrol-based stilbenes were identified. Wine lees have been revealed as an interesting source of flavonol aglycones and pyranoanthocyanins. The best sample preparation technique prior to the extraction of phenolic compounds, with regard to the maintenance of phenolic compound profiles and concentrations, was freeze-drying. However, in the case of lees, spray-drying showed to be also effective in the preservation of phenolic compounds and is a less expensive technique. Oven-drying at 50. °C should be avoided if there is interest in using winemaking by-products for further purposes, since phenolic compound concentrations were strongly reduced by thermal degradation. © 2014 Elsevier Ltd. Source


Bordiga M.,University of Piemonte Orientale | Gomez-Alonso S.,Fundacion Parque Cientifico y Tecnologico de Albacete | Gomez-Alonso S.,University of Castilla - La Mancha | Locatelli M.,University of Piemonte Orientale | And 4 more authors.
Food Research International | Year: 2014

The three principal black rice varieties grown in Piedmont (Artemide, Venere, Nerone) have been studied in comparison with other three at different pigmentations: red (Ermes, Russ) and white, partially refined (Selenio). The extracts from these six different cultivars, processed as "husked" rices, were analyzed by high-performance liquid chromatography coupled with diode array detection and electrospray ionization-mass spectrometry (HPLC-DAD-ESI-MS/MS). Both qualitative and quantitative characterizations of the flavonoids (anthocyanins, flavonols, and flavan-3-ols) and non-flavonoid (hydroxycinnamic acids) phenolic compounds were achieved. 2,2-Diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity and total phenolic content were evaluated to determine the antioxidant properties of different rices. Black rice showed higher contents of phenolics, flavonoids, and anthocyanins showing higher antioxidant activity when compared to white and partially if compared to red rices. Cyanidin-3-glucoside was the major anthocyanin in black rice grains, followed by peonidin-3-glucoside and cyanidin-3-rutinoside. With respect to the diglycosyl anthocyanins, cyanidin-3-O-gentiobioside was confirmed and quantified in black varieties. Significant differences in phytochemical content and antioxidant activity were achieved also among the three black varieties. The results demonstrate that the black rice varieties contain a rich heterogeneous mixture of phytochemicals which may provide a basis for the potential health benefits, and highlights the rice as a functional food. © 2014 Elsevier Ltd. Source


Rebello L.P.G.,Federal University of Fluminense | Lago-Vanzela E.S.,Sao Paulo State University | Barcia M.T.,University of Campinas | Ramos A.M.,Federal University of Vicosa | And 6 more authors.
Food Research International | Year: 2013

The grape is considered a major source of phenolic compounds when compared to other fruits and vegetables, however, there are many cultivars with distinct characteristics directly linked to phenolic profile. Thus, the present study aimed to identify and quantify, for the first time and in detail, the phenolic compounds present in the skin, flesh and seeds of BRS Violeta grape berry using combination of SPE methodologies and analytical HPLC-DAD-ESI-MS/MS. The study was extended to the different berry parts and the most important grape and wine phenolic families, and has revealed interesting features. Violeta grape has a very thick skin (46% of grape weight) that accumulated the most of grape phenolic compounds: great amount of anthocyanins (3930. mg/kg, as malvidin 3,5-diglucoside), together with also important amounts of flavonols (150. mg/kg, as quercetin 3-glucoside), hydroxycinnamic acid derivatives (HCAD; 120. mg/kg, as caftaric acid), and proanthocyanidins (670. mg/kg, as (+)-catechin); in contrast, it seems to be a low resveratrol producer. Violeta grape seeds accounted for similar proportions of low molecular weight flavan-3-ols (mainly monomers; 345. mg/kg, as (+)-catechin) and proanthocyanidins (480. mg/kg, as (+)-catechin). Violeta grape is a teinturier cultivar, but it only contained traces of anthocyanins and low amounts of all the other phenolic types in its red-colored flesh. The anthocyanin composition of Violeta grape was dominated by anthocyanidin 3,5-diglucosides (90%). Within flavonols, myricetin-type predominated and kaempferol-type was missing. In addition to expected hydroxycinnamoyl-tartaric acids, several isomeric esters of caffeic and p-coumaric acids with hexoses were tentatively identified, accounting for relevant proportions within the pool of HCAD. Although pending of further confirmation over successive vintages, the aforementioned results suggest that BRS Violeta grape cultivar could be considered an interesting candidate for the elaboration of highly colored and antioxidant-rich grape juices and wines. © 2013 Elsevier Ltd. Source

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