Nutrition and Bromatology Group

Ourense, Spain

Nutrition and Bromatology Group

Ourense, Spain
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Figueiredo-Gonzalez M.,Nutrition and Bromatology Group | Cancho-Grande B.,Nutrition and Bromatology Group | Simal-Gandara J.,Nutrition and Bromatology Group
Food Chemistry | Year: 2013

The off-vine drying is one of the most important steps in the production of a high quality naturally sweet wine. However, only few studies have analyzed the changes in colour and phenolic compounds of the grapes throughout the process. In this work, UV/Vis spectrophotometry and HPLC/DAD-ESI/MS were applied to determine, respectively, the evolution of colour and phenolic compounds in the red grapes of Garnacha Tintorera during the raisining process. The total water loss in 83 days was about 62% and the sugar concentration rose from 225 to 464 g L-1. Browning and low-medium molecular weight compounds increase during the dehydration process. In CIELab coordinates, raisining decreases a. (red/green) and lightness and increases b. (yellow/blue), colour saturation and hue angle. In general, most of the phenolic compounds determined (anthocyanins, flavonols, esters of hydroxycinnamic acids, flavan-3-ol monomers and proanthocyanidins) increase but to a lesser extent than expected because of the water loss of the grapes during drying. The lower increase was observed for esters of hydroxicinnamic acids suggesting these compounds could undergo strong enzymatic degradation. Despite this, both the terminal and the extension subunit compositions show little changes, while the mean degree of polymerization of proanthocyanidins decreases as raisining progresses. © 2013 Elsevier Ltd. All rights reserved.

Figueiredo-Gonzalez M.,Nutrition and Bromatology Group | Regueiro J.,Nutrition and Bromatology Group | Cancho-Grande B.,Nutrition and Bromatology Group | Simal-Gandara J.,Nutrition and Bromatology Group
Food Chemistry | Year: 2014

Sweet wines are traditionally elaborated in Galicia (the N.W. corner of Spain). The denomination of origin (DO) Valdeorras, one of the five DOs in Galicia, wants to promote the production and marketing of new sweets wines. The first one is made with dried red grapes Vitis vinifera L. Garnacha Tintorera (GNSW); this cultivar is a teinturier cultivar which has excellent potential to produce wines from raisined grapes. The second one, a fortified sweet wine aged in oak barrels (GFSW). Additionally a dry young wine (GBW) was produced from the same variety. Their aroma profiles and chromatic characteristics (determined by simple spectrophotometric methods) have been previously established. Now, proanthocyanidins, flava-3-ol monomers, anthocyanins, phenolic acids, flavonols and resveratrol were determined by HPLC, for the same three wines. The highest concentration of total proanthocyanidins (PAs) was evaluated in the GBW (525 mg L 1), which was about 2-fold the concentration in the GNSW (236 mg L 1) and about more 10-fold the concentration in the GFSW (44 mg L 1). No apparent difference in the aDP (mean degree of polymerisation) was observed for the GBW (1.9) and the GNSW (2.1), whereas a slightly lower value was obtained for the GFSW (1.5). Total anthocyanin concentration was described as follow as GBW: 390 mg L 1 GNSW: 57 mg L 1 GFSW: 25 mg L 1, which indicates that sweet wines were polymerised in great extent. Only vitisin A and B were found the main concentration in GFSW when compared to GBW by the ageing process. In sweet wines, phenolic acids (hydroxybenzoic and hydroxycinnamic acids) and flavonols were lowest when compared to GBW and resveratrol not was found in sweet wines. © 2013 Elsevier Ltd. All rights reserved.

Rodrigues A.S.,Escola Superior Agraria de Ponte de Lima | Perez-Gregorio M.R.,Nutrition and Bromatology Group | Garcia-Falcon M.S.,Nutrition and Bromatology Group | Simal-Gandara J.,Nutrition and Bromatology Group | Almeida D.P.F.,University of Porto
Food Control | Year: 2010

Onions are major sources of flavonoids in the human diet. However, little information is available regarding the effects of long-storage or exposure to specific stress conditions on flavonoids content of onions. The aim of this work was to assess the effect of different post-harvest treatments on the flavonoid composition of two Portuguese landrace varieties of onions ('Branca da Póvoa' and 'Vermelha da Póvoa'). The evolution of the content of some major flavonols and anthocyanins was measured in red and white onion bulbs (from 2005 and 2006 harvests) during 7 months of storage, under refrigerated and under traditional bulk storage in the field. Total flavonols increased up to 64% after 6 or 7 months of storage. This increase was especially important during the first 3 months of storage (58% increase). In red onions, with the largest concentrations in flavonols, bulbs stored in the field reached higher levels of flavonoids (64% maximum) than refrigerated onions (40% maximum). For red onions, the increase after 6-months storage usually has place when the flavonol post-harvest levels are low (40-64% increase), whereas for white onions the increase after 6-months storage is important for onions with higher levels after harvest (44-60% increase). These results suggest that storage at fluctuating ambient temperatures can positively affect flavonol metabolism, while keeping the flavonols profile. There were no significant modifications of the total levels of anthocyanin pigments after 6 months of storage of red bulbs, but after 7 months total anthocyanin content was reduced between 40% and 60%. Post-harvest UV (40 kJ/m2, 1 week storage) and ethylene (100 μL/L for 24 h, 2 months storage) treatments did only affect the flavonol content of the edible portion of onions with a profitable increase. © 2009 Elsevier Ltd. All rights reserved.

Gonzalez-Rodriguez R.M.,Nutrition and Bromatology Group | Gonzalez-Barreiro C.,Nutrition and Bromatology Group | Rial-Otero R.,Nutrition and Bromatology Group | Regueiro J.,Nutrition and Bromatology Group | And 3 more authors.
CYTA - Journal of Food | Year: 2011

The influence of different concentrations of two new fungicides (metiram and pyraclostrobin) on the fermentative activity of Saccharomyces cerevisiae yeast during winemaking process has been evaluated through in vitro assays. These fungicides were assayed as pure active compounds (single and in combination) and as a commercial formulation which contains both fungicides (55% metiram + 5% pyraclostrobin). The presence of pyraclostrobin pure standard in the culture medium, at the highest concentration evaluated (10 mg/L), increased the biomass and ethanol production rate. No effect on the alcoholic fermentation was observed for metiram pure standard due to its low solubility in the synthetic medium. However, a total inhibition of yeast growth was observed in presence of ge;40 mg/L of the commercial formulation. © 2011 Taylor & Francis.

Rios-Covian D.,Institute Productos Lacteos Of Asturias | Sanchez B.,Institute Productos Lacteos Of Asturias | Sanchez B.,Nutrition and Bromatology Group | Salazar N.,Institute Productos Lacteos Of Asturias | And 4 more authors.
Frontiers in Microbiology | Year: 2015

Bacteroides is among the most abundant microorganism inhabiting the human intestine. They are saccharolytic bacteria able to use dietary or host-derived glycans as energy sources. Some Bacteroides fragilis strains contribute to the maturation of the immune system but it is also an opportunistic pathogen. The intestine is the habitat of most Bifidobacterium species, some of whose strains are considered probiotics. Bifidobacteria can synthesize exopolysaccharides (EPS), which are complex carbohydrates that may be available in the intestinal environment. We studied the metabolism of B. fragilis when an EPS preparation from bifidobacteria was added to the growth medium compared to its behavior with added glucose. 2D-DIGE coupled with the identification by MALDI-TOF/TOF evidenced proteins that were differentially produced when EPS was added. The results were supported by RT qPCR gene expression analysis. The intracellular and extracellular pattern of certain amino acids, the redox balance and the a-glucosidase activity were differently affected in EPS with respect to glucose. These results allowed us to hypothesize that three general main events, namely the activation of amino acids catabolism, enhancement of the transketolase reaction from the pentose-phosphate cycle, and activation of the succinate-propionate pathway, promote a shift of bacterial metabolism rendering more reducing power and optimizing the energetic yield in the form of ATP when Bacteroides grow with added EPS. Our results expand the knowledge about the capacity of B. fragilis for adapting to complex carbohydrates and amino acids present in the intestinal environment. © 2015 Rios-covian, Sanchez, Salazar, Martinez, Redruello, Gueimonde and De los Reyes-Gavilan.

Pose-Juan E.,Nutrition and Bromatology Group | Rial-Otero R.,Nutrition and Bromatology Group | Paradelo M.,Soil and Agricultural Science Group | Simal-Gandara J.,Nutrition and Bromatology Group | And 2 more authors.
Journal of Hazardous Materials | Year: 2010

The objective of this work is to asses the sorption of metalaxyl applied as a copper oxychloride (CO)-metalaxyl formulation, for a set of selected soils devoted to vineyards. The method involved batch incubation of soils suspended with a commercial copper oxychloride-metalaxyl-based fungicide in 0.01 M CaCl2. Afterwards, the metalaxyl concentration remaining in solution was determined by high-performance liquid chromatography (HPLC). The amount of dissolved metalaxyl in the fungicide suspension depends mainly on the soil pH, its potential acidity, and the cation exchange capacity. Of the approx. 20% metalaxyl retained by the solid colloids, the effect of organic matter colloids in soils (15-20 mg kg-1) had a poor contribution (six times lower) than the copper oxychloride colloids (40%, w/w) in the commercial fungicide formulation (100-130 mg kg-1). When comparing these retention data with the behaviour of metalaxyl used as a technical grade fungicide of about 100% purity (10-15 mg kg-1 in solids), it is clear that the commercial formulation increases a 30% retention of metalaxyl by soil (15-20 mg kg-1 in solids). The overall effect of the metalaxyl formulation plus soil show values of 10 times higher retention than technical grade-metalaxyl plus soil. Commercial formulation can decrease the mobility of soluble metalaxyl in agricultural soils with regard to the expected values obtained from batch studies using analytical grade-metalaxyl. Therefore, the effect of surfactants should be considered in the assessment of water contamination by the pesticides used in agriculture. © 2009 Elsevier B.V. All rights reserved.

Capelo J.L.,REQUIMTE | Capelo J.L.,Nutrition and Bromatology Group | Carreira R.J.,REQUIMTE | Fernandes L.,REQUIMTE | And 4 more authors.
Talanta | Year: 2010

Nowadays isotopic 18O-labeling of peptides has recalled the attention of researchers due to its simplicity of application and high versatility for proteomics studies. Protein quantification, differential peptide mass mapping, studies regarding proteins overexpressed or underexpressed, or the searching of biomarkers can be accomplished by using 18O-labeling. In this critical review we comment on the different ways in which 18O-labeling can be done, highlighting the key parameters of the different sample treatments to obtain a reliable and reproducible labeling. In addition we describe and compare the latest improvement in terms of sample treatment that allows to reduce the handling and to increase the throughput for this sample treatment. Finally, we hypothesize on the future trends of these methods under the light of the new technological advances to speed protein cleavage. © 2009 Elsevier B.V. All rights reserved.

The suitability of hyphenated USAED with HPLC separation and ET-AAS determination as a new rapid methodology for Se control in Se-enriched food supplements is demonstrated. Total Se determination and Se speciation are accomplished in a single sample treatment using low sample amounts (ca. 10 mg), and low extracting volume (1 mL). The total Se content in seven of the 10 Se-enriched supplements studied was in agreement with the values obtained after microwave pressurized acid digestion, MW, (test t, p = 0.05). The Se species studied were Se(IV), Se(VI), SeMet, SeMeSeCys, and SeCys2, being some of the most common found in the 10 supplements studied. Although SeMet was the Se species expected to be present at the highest concentration in most Se-enriched food supplements, we detected it in only three of the 10 samples studied. In the other seven samples, two of them had Se(IV) as the main Se species. The other five supplements had Se species that did not match with any of the five standards selected by us. We have also systematically demonstrated that ultrasonication does not alter the following Se species: Se(IV), Se(VI), SeMet, SeMeSeCys, and SeCys2. The new procedure can be easily adapted to more Se species and can be routinely used for Se control in Se-enriched food supplements. Concerning the supplements studied, our results suggest that stricter control on the Se content in enriched food supplements in terms of Se species will need to become mandatory. © 2009 Elsevier Ltd. All rights reserved.

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