Sunday 25 January 2015

Effect of crushed mussel shell addition on bacterial growth in acid polluted soils

Applied Soil Ecology, 85 (2015) 65-68

We applied three different doses of crushed mussel shell (CMS) on two Cu-polluted acid soils to study the effect of these amendments on the growth of the bacterial community during 730 days. Soil pH increased in the short and medium term due to CMS addition. In a first stage, bacterial growth was lower in the CMS-amended than in the un-amended samples. Thereafter, bacterial growth increased slowly. The soil having the highest initial pH value (4.5) showed the first significant increase in bacterial growth 95 days after the CMS amendment. However, in the soil with the lowest initial pH value (3.8) bacterial growth increased significantly only after 730 days from the CMS addition. The highest dose of CMS caused that, at the end of the incubation period, pH value have increased 2 units, whereas bacterial growth was 4–10 times higher. In view of these results, CMS amendment could be considered as an agronomic sound practice for strongly acid soils (pH <4.5).

Wine Aroma Compounds in Grapes: A Critical Review

Critical Reviews in Food Science and Nutrition, 2015, 55(2), 202-218

Volatile organic compounds are vital to wine quality, determining their aroma and varietal characteristics. Which are present, and in what quantity, depends on the cultivar, the situation and soil of the vineyard, weather, cultivation methods, and wine-making practices. Here, we review the literature on the development of wine aroma compounds in grapes, and how it is affected by the above-named factors. Increasing understanding of these processes at the molecular level will aid vine growers in the optimal selection of harvest dates and other decisions favoring the consistent production of balanced, flavorful berries. 

Thursday 22 January 2015

An axisymmetric model for the analysis of dynamic surface tension

RSC Adv., 2015, 5, 7921–7931 

A quantitative treatment of dynamic surface tension data has been carried out with different mathematical approaches taking into account a diffusion-controlled mechanism. The classical model has been modified in order to achieve a better description of the experimental conditions by considering a finite diffusion domain. The domain has been fixed keeping the restriction that the surfactant concentration in this region should remain constant after the adsorption at the air–water interface, in such a way that the number of surfactant unimers is 30 times the number adsorbed at the interface. The finite diffusion restriction has been used both in 1D and axisymmetric models, the latter one being the most accurate and needing a smaller diffusion domain since it considers surfactant adsorption at a sphere resembling the physical experiments. A distorted sphere geometry taking into account the Laplace–Young equation has also been studied.

Sunday 18 January 2015

A Review on the Fermentation of Foods and the Residues of Pesticides—Biotransformation of Pesticides and Effects on Fermentation and Food Quality

Critical Reviews in Food Science and Nutrition, 2015, 55(6), 839-863

Residues of pesticides in food are influenced by processing such as fermentation. Reviewing the extensive literature showed that in most cases, this step leads to large reductions in original residue levels in the fermented food, with the formation of new pesticide by-products. The behavior of residues in fermentation can be rationalized in terms of the physical-chemical properties of the pesticide and the nature of the process. In addition, the presence of pesticides decrease the growth rate of fermentative microbiota (yeasts and bacterias), which provokes stuck and sluggish fermentations. These changes have in consequence repercussions on several aspects of food sensory quality (physical-chemical properties, polyphenolic content, and aromatic profile) of fermented food. The main aim of this review is to deal with all these topics to propose challenging needs in science-based quality management of pesticides residues in food.

Thursday 15 January 2015

El consumo moderado de licor de hierbas aporta beneficios saludables

Los análisis realizados sobre distintos derivados del orujo -licor de hierbas y aguardientes envejecidos- demuestran que un consumo moderado de estas bebidas pueden aportar beneficios para la salud. Es una de las conclusiones de la tesis de doctorado presentada por Raquel Rodriguez, bajo la dirección de los doctores José Manuel Domínguez y Sandra Cortés (ambos miembros del CIA). Dicha tesis se encuentra balada por 7 publicaciones internacionales en revistas de alto impacto y sus conclusiones ya están en manos del Consello Regulador de Augardentes de Galicia.

Este trabajo, además de arrojar luz sobre las características que puede aportar cada planta al producto final abre la puerta a análisis más amplios e incluso a la elaboración de legislación sobre las concentraciones más aconsejables.

Fuente: Faro de Vigo

Tuesday 13 January 2015

La mejor receta para el licor de hierbas

Un trabajo pionero de la Universidad analiza la elaboración de las bebidas tradicionales derivadas del orujo y determina las propiedades que aportan las plantas medicinales.

Son productos icónicos de la tradición cultural y gastronómica gallega y gozan de calidad reconocida más allá de nuestras fronteras. Sin embargo, su composición y procedimiento todavía no habían sido objeto de análisis científico. Una pormenorizada investigación de la Universidad de Vigo aborda por primera vez el proceso de elaboración de las bebidas derivadas del orujo -licores de hierbas y aguardiente envejecido- con resultados de interés para que las bodegas obtengan las propiedades deseadas y además puedan reducir costes y tiempo.

La química vagueas Raquél Rodríguez es la autora de un proyecto desarrollado durante más de cuatro años como integrante del grupo de Biotecnología Alimentaria del campus ourensano en sus integrado dentro del CIA.

Fuente: Faro de Vigo

Sunday 11 January 2015

The measure and control of effects of botryticides on phenolic profile and color quality of red wines

Food Control 2015, 50, 942-948

The effect of the residues of two fungicides (mepanipyrim and fenhexamid) on the color and phenolic profile of Tempranillo and Graciano red wines has been studied. To evaluate possible modifications in color and phenolic composition of wines, control wines (not treated) and wines elaborated with spiked musts were analyzed. Thereby, changes in the color parameters of CIELab space were observed in the wines treated with mepanipyrim and also in Tempranillo wines treated with fenhexamid. In general, the anti-fungal substances had different effects depending on the cultivar and on the phenolic compound analyzed; being monomeric anthocyanins and flavan-3-ol monomers the compounds more affected by the presence of these fungicides.

Sunday 4 January 2015

Characterisation of extra virgin olive oils from Galician autochthonous varieties and their co-crushings with Arbequina and Picual cv.

Food Chemistry (2015) 176, 493-503

The current trend of the olive oil market is the production of high quality extra from traditional minor olive varieties with peculiar and differentiated characteristics (especially with respect to the aromatic and phenolic composition). In this way, the interest of Galician oil producers (NW Spain) in recovering old autochthonous Local olive fruits has increased substantially in recent years. In order to investigate the potential of the Local olives by either producing high quality monovarietal oils or mixing with the most widespread olives in Galicia (Arbequina and Picual cv.), quality indices, and fatty acid composition as well as volatile and phenolic profiles were determined and compared. All EVOOs studied in this work can be considered as "extra virgin olive oil" due to quality indices fell within the ranges established in legislation. Picual and Local olive oils as well as those resulting from their co-crushing reach values which are required by EU legislation to add the specific health claim on the oil label. Co-crushing Picual:Local (80:20) provided a significant enhancement of grass and apple nuances and a decrease of banana notes with respect to Picual oils. The co-crushing process improved sensory and health properties of Picual extra virgin olive oils. The effect of co-crushing on phenolics, ester volatiles and banana nuances cannot be easily modulated, contrary to quality indices and fatty acid composition, both changing linearly in strict correlation with the fruit mass ratio.