630 research outputs found

    Combine use of Selected Schizosaccharomyces pombe and Lachancea thermotolerans Yeast Strains as an Alternative to the Traditional Malolactic Fermentation in Red Wine Production

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    Most red wines commercialized in the market use the malolactic fermentationprocess in order to ensure stability from a microbiological point of view. In this secondfermentation, malic acid is converted into L-lactic acid under controlled setups. Howeverthis process is not free from possible collateral effects that on some occasions produceoff-flavors, wine quality loss and human health problems. In warm viticulture regions suchas the south of Spain, the risk of suffering a deviation during the malolactic fermentationprocess increases due to the high must pH. This contributes to produce wines with highvolatile acidity and biogenic amine values. This manuscript develops a new red winemakingmethodology that consists of combining the use of two non-Saccharomyces yeast strains asan alternative to the traditional malolactic fermentation. In this method, malic acid is totallyconsumed by Schizosaccharomyces pombe, thus achieving the microbiological stabilizationobjective, while Lachancea thermotolerans produces lactic acid in order not to reduce andeven increase the acidity of wines produced from low acidity musts. This technique reducesthe risks inherent to the malolactic fermentation process when performed in warm regions.The result is more fruity wines that contain less acetic acid and biogenic amines than thetraditional controls that have undergone the classical malolactic fermentation

    Innovación en la detección de Dekkera/Brettanomyces para vinos tintos

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    Existen en la actualidad diversos métodos empleados para la detección de Dekkera/Brettanomyces con numerosas ventajas de distinta índole pero no exentos de algunos inconvenientes, por lo que es necesario profundizar en la interpretación de los resultados de los mismos

    Piranoantocianos vinilfenólicos en vinos tintos utilizando levaduras HCDC+.

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    Los piranoantocianos vinilfenólicos son aductos de elevada estabilidad, con interesantes propiedades para la mejora del color en vinos tintos, y que se forman por condensación entre ácidos hidroxicinámicos o sus respectivos vinilfenoles y antocianos procedentes de la uva. Inicialmente se pensaba que la única ruta de formación era exclusivamente química (Schwarz, 2003) en un lento proceso a partir de ácidos hidroxicinámicos, que inducía a cantidades muy pequeñas durante el periodo de envejecimiento de los vinos tintos y podían por tanto ser usadas como age-markers. Recientemente se ha demostrado (Morata et al, 2006 y 2007) que algunas cepas de Saccharomyces spp seleccionadas con alta actividad hidroxicinamato descarboxilasa (HCDC) pueden acelerar la formación de aductos vinilfenólicos durante la fermentación. Estas levaduras descarboxilan los ácidos fenólicos formando vinilfenoles de elevada reactividad que espontáneamente condensan con antocianos de la uva formando una gran variedad de aductos vinilfenólicos dependiendo del tipo de antociano y del ácido hidroxicinámico precursor. Cuantitativamente los derivados más importantes son los del malvidin-3-O-glucosido. Adicionando ácidos hidroxicinámicos a las muestras se verifica que el aducto que se forma en mayor cantidad es el malvidin-3-O-glucosido-4-vinilguaiacol, siendo además el que produce mayor incremento de la intensidad colorante reduciendo a su vez las tonalidades amarillas en vinos. La utilización de cepas de Saccharomyces HCDC+ con o sin adiciones de ácidos hidroxicinámicos, puede constituirse en una interesante herramienta para mejorar el color de vinos tintos

    Detección de Dekkera / Ibrettanomyces en Vinos Tintos

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    Existen en la actualidad diversos métodos empleados para la detección de Dekkera/Brettanomyces con numerosas ventajas pero no exentos de inconvenientes tales como umbrales de detección, diferenciación entre células viables y muertas, carácter no preventivo, falsos positivos, tiempos de espera, evaluación insegura (por olfato humano o visual) y contaminaciones por hongos oportunistas. Con objeto de aportar soluciones a esta problemática se han combinado un medio selectivo-diferencial líquido y técnica HPLC/DAD con objeto de evaluar la “Actividad potencial hidroxicinamato descarboxilasa y vinilfenol reductasa existente en un vino”, mejorando algunos de los aspectos anteriores como la cuantificación de poblaciones pequeñas (1 ufc/50ml), trabajo con volúmenes grandes, y detección únicamente de células viables (verdaderas responsables de la formación de etilfenoles)

    Reduction of 4-ethylphenol concentration using lyophilized yeast biomasses as bioadsorbent: influence on the anthocyanin contents and chromatic parameters

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    A new investigation trend, based on the parietal adsorption activity showed by yeast cellwalls, opens up the possibility to use yeast lees or derived products like inactive dry yeast preparations to reduce 4-ethylphenol concentrations in wines. These type of natural products entails an interesting eco-friendly alternative to common physical treatments. In this work the bioadsorption capacity of 4-ethylphenol of different wine yeast biomasses have been studied -Saccharomyces cerevisiae G37 and Schizosaccharomyces pombe 936-, in order to diminish the negative impact on the sensorial profile of this type of compound (Figure 1). the repercussions of this palliative treatment over the chromatic properties and anthocyanin concentration have also been studied by means of UV-Vis and HPLC-PDAD/ESI-MS analysi

    Influence of sequential and mixed fermentations with non-Saccharomyces yeasts on the sensory profile of red wine

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    The aim of this work is to evaluate the influence of S. pombe and T. delbrueckii species on the sensory quality of red wine when used in sequential and mixed fermentations with S. cerevisiae

    Identifying yeats belonging to the Brettanomyces/Dekkera genera through the use of selective-differential media

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    The purpose of this work was to compare and optimise different selective and differential media to aid in isolating spoilage yeasts belonging to the Brettanomyces/Dekkera genera. Growth media containing selective and differential factors were employed. These were inoculated with strains of yeast representing Spanish oenological microbiota. Lastly, some of these isolation media were successfully applied in 24 types of wine with a high ethylphenol content, all of which were from the Haro Oenological Station (La Rioja, Spain). p-coumaric acid was determined using High performance liquid chromatography-photodiode-array detection-electrospray ionization mass spectrometry (HPLC-DAD-ESI/MS); 4-ethylphenol by using Solid phase micro extraction-gas chromatography-mass spectrometry (SPME-GC-MS); and the rest of the analysis was carried out using official OIV methodology. Actidione is the most effective selective factor for isolating Brettanomyces/Dekkera yeast genera. Other secondary selective factors (selective carbon sources, sorbic acid and ethanol as a microbicide agent) may be used successfully to eliminate potential false positivities; however, they slow growth and delay the time to obtain results

    Physiological features of Schizosaccharomyces pombe of interest in the making of white wines

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    This work studies the physiology of Schizosaccharomyces pombe strain 938 in the production of white wine with high malic acid levels as the sole fermentative yeast, as well as in mixed and sequential fermentations with Saccharomyces cerevisiae Cru Blanc. The induction of controlled maloalcoholic fermentation through the use of Schizosaccharomyces spp. is now being viewed with much interest. The acetic, malic and pyruvic acid concentrations, relative density and pH of the musts were measured over the entire fermentation period. In all fermentations in which Schizo. pombe 938 was involved, nearly all the malic acid was consumed and moderate acetic concentrations produced. The urea content and alcohol level of these wines were notably lower than in those made with Sacch. cerevisiae Cru Blanc alone. The pyruvic acid concentration was significantly higher in Schizo. pombe fermentations. The sensorial properties of the different final wines varied widely

    Reducción de etilfenoles por formación de piranoantocianos vinilfenólicos

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    Los géneros Brettanomyces/Dekkera son responsables de la aparición de aromas fenólicos [Figura 1]. Dichos olores son resultado de la evolución de ácidos hidroxicinámicos hacia etilfenoles como consecuencia de las actividades hidroxicinamato descarboxilasa (HCDC) y vinilfenolreductasa (VphR) de estos géneros [Figura 2]. El objetivo del trabajo fue facilitar la formación de piranoantocianos vinilfenólicos usando cepas de Saccharomyces HCDC+ (pero VphR-) , con objeto de reducir el contenido inicial de ácidos hidroxicinámicos del vino durante la fermentación y prevenir de esta forma la formación de etilfenoles en caso de contaminación por Brettanomyces/Dekkera

    Acceleration of ageing on lees in red wines by application of ultrasounds

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    A transfer of parietal polysaccharides and mannoproteins is produced during aging on lees [1]. This transfer of compounds to wine is carried out after cell death. It comes to breakdown of polysaccharides from cell wall (yeast autolysis). This technique increases the density in wines [2] and gives more body and structure. Interactions between yeast polysaccharides and wine tannins will result in decrease of tannic perception (decrease of astringency). Increase of varietal characteristics is produced. The main disadvantage of the ageing on lees is the time that the process requires. Usually, nine months are necessary at least for obtaining a noticeable effect in wines. The objective of this work is the acceleration of this process using ultrasounds to lyse the yeast cell wall. In addition, the influence of this technique in different red wine quality parameters was studied
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