Selection of Native Non-Saccharomyces Yeasts with Biocontrol Activity against Spoilage Yeasts in Order to Produce Healthy Regional Wines

Two major spoilage yeasts in the wine industry, Brettanomyces bruxellensis and Zygosaccharomyces rouxii, produce off-flavors and gas, causing considerable economic losses. Traditionally, SO2 has been used in winemaking to prevent spoilage, but strict regulations are in place regarding its use due to its toxic and allergenic effects. To reduce its usage researchers have been searching for alternative techniques. One alternative is biocontrol, which can be used either independently or in a complementary way to chemical control (SO2). The present study analyzed 122 native non-Saccharomyces yeasts for their biocontrol activity and their ability to be employed under fermentation conditions, as well as certain enological traits. After the native non-Saccharomyces yeasts were assayed for their biocontrol activity, 10 biocontroller yeasts were selected and assayed for their ability to prevail in the fermentation medium, as well as with respect to their corresponding positive/negative contribution to the wine. Two yeasts that satisfy these characteristics were Wickerhamomyces anomalus BWa156 and Metschnikowia pulcherrima BMp29, which were selected for further research in application to mixed fermentations.Fil: Kuchen, Benjamín. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Toro, Maria Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentin

Bioprospecting of the probiotic potential of yeasts isolated from a wine environment

Autochthonous yeasts of oenological origin are adapted to highly stressful and selective environments, which makes them potential candidates for probiotics. The objective of the present study was to explore the probiotic potential of 96 native yeasts of oenological origin, their biosafety, resistance to gastrointestinal tract conditions and adhesion properties. Regarding biosafety, 66 isolates shown negative hemolytic activity, negative urease activity and susceptibility to 3 or more antifungals. After the gastrointestinal resistance test, 15 isolates were selected that showed growth at different temperatures, tolerance to low pH and the presence of bile salts in in vitro tests. In general, survival after simulated conditions of the gastrointestinal tract was high and more restrictive was the duodenal. The results of the adhesion properties showed highly variable hydrophobicity and a high percentage of autoaggregation at 24 h. The maximum production of biofilm was detected in the Pichia strains. Of a total of 96 yeast strains, 15 non-Saccharomyces yeasts presented suitable properties as probiotic candidates. The native winemaking strains performed better than the reference probiotic strain, Saccharomyces cerevisiae var. boulardii CNCM I-745, which reaffirms that these strains are promising probiotic candidates and further studies are necessary to confirm their probiosis.Fil: Vergara Alvarez, Silvia Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Leiva Alaniz, María José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mancha Agresti, Pamela. Centro Federal de Educação Tecnológica; BrasilFil: Cristina Nally, María. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Combination of pre-fermentative and fermentative strategies to produce Malbec wines of lower alcohol and pH, with high chemical and sensory quality

The climatic conditions in some wine regions imply in many cases the important delay in the harvest date to achieve an appropriate phenolic maturity in red grape varieties, leading to wines with high pH and alcohol content. This problem, associated with low acceptation for some consumers and chemical/microbial instability, can be addressed from a viticultural, oenological, or microbiological level. The present study aimed to provide a technological alternative, combining vintages blending and inoculation of native yeasts, for reducing simultaneously the alcohol content and the pH of Malbec wines without altering the chemical and sensory quality. Sauvignon blanc grapes harvested at the beginning of ripening (2017 season) were employed to obtain a wine with high acidity and low alcohol content (LW), that was blending with Malbec grapes of full phenolic maturity. Malbec grapes were harvested at two different moments (1H, 13.0 % v/v; 2H, 14.5 % v/v, probable alcohol), and elaborated following a standard protocol. From 2H, a part of the grape juice was removed and replaced with LW as a strategy for alcohol reduction (2RW). Consequently, it was obtained nine wines by triplicate combining 1H, 2H, 2RW musts with three fermentative strategies: CI, co-inoculation of Hanseniaspora uvarum BHu9/Saccharomyces cerevisiae BSc114 native yeasts; NS, S. cerevisiae BSc114 native yeast; and CS, S. cerevisiae EC 1118 commercial yeast. We found that 2RW wines, fermented with different yeast strains, showed similar levels of total phenols, tannins, anthocyanins, and polymeric pigments concerning control wines (2H). In all cases, those wines presented greater phenolic potential compared to wines from 1H. At the same time, the pre-fermentative strategy of vintages blending produced wines with 1.4 % v/v less alcohol than 2H wines, also achieving a pH decrease of 0.3 units. Combined treatments with native strains, especially as single inoculum (2RW–NS), were the most efficient in reducing both parameters, showed higher tannins, anthocyanins levels, and colour saturation, without affecting the sensory quality, in terms of aromas and mouthfeel. In conclusion, the strategies proposed could be simple and economic tools, for red wines production with low alcohol content, and high chemical and organoleptic quality, capable of competing and satisfying market needs.EEA MendozaFil: Fanzone, Martí­n Leandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Sari, Santiago Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Mestre Furlani, Maria Victoria. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Mestre Furlani, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Catania, Anibal Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Catelén, María J. Trapiche Winery. Grupo Peñaflor S.A.; ArgentinaFil: Jofre, Viviana Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: González-Miret, María Lourdes. Universidad de Sevilla. Facultad de Farmacia. Department of Nutrition and Food Science. Food Colour & Quality Laboratory; EspañaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Combina, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Vazquez, Fabio. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Maturano, Yolanda Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Obtención de vinos con reducida concentración de etanol mediante el uso de levaduras Saccharomyces y no-Saccharomyces

El cambio climático global ha conducido a que las temperaturas medias sean cada vez más elevadas y exista menor régimen de precipitaciones en las regiones cálidas del planeta. Este hecho afecta a la agricultura de forma directa, en especial la vitivinicultura. Como consecuencia de este fenómeno, la uva experimenta un adelanto en la madurez industrial (relación azúcar/acidez), respecto a la maduración tecnológica óptima (madurez fenólica, concentración de aromas típicos). Para responder la demanda de los consumidores de vino, la cual esta regida por productos con mayor complejidad aromática y refrescancia, adecuado color y cuerpo, se debe retardar la vendimia hasta lograr la madurez tecnológica adecuada. Como consecuencia las uvas alcanzan elevada concentración de azúcares, obteniéndose de esta manera vinos con alto contenido alcohólico. La concentración elevada de etanol ocasiona una disminución de la calidad del producto (enmascara aromas), problemas de salud y aumento de costos para el consumidor. Una estrategia factible para lograr la disminución del contenido final de etanol en el vino, es el empleo de levaduras seleccionadas sobre la base de sus rasgos metabólicos. En el presente estudio se evaluaron 114 aislamientos de levaduras nativas no-Saccharomyces (NS) y 4 aislamientos de S. cerevisiae, con el fin de conformar co-inóculos secuenciales para obtener vinos con menor graduación alcohólica. Para formular los cultivos secuenciales iniciadores entre los aislamientos seleccionados se optimizó el tiempo de permanencia de la levadura NS previo a la inoculación de S. cerevisiae, la concentración inicial de células a inocular de la levadura NS y la temperatura del sistema fermentante al momento de su inoculación. Las estrategias optimizadas fueron validadas en mosto cv Malbec esterilizado (con el fin de evaluar específicamente la acción de los co-inóculos) y fresco (situación real de fermentación). Una fermentación conducida con BSc114 fue empleada como control. Los vinos obtenidos fueron sometidos a evaluación sensorial por un panel entrenado y análisis aromático empleando GC-MS. Las levaduras seleccionadas fueron H. uvarum BHu9, C. membranifaciens BCm71 y S. cerevisiae BSc114. La estrategia de inoculación óptima para BHu9/BSc114 consistió en: tiempo de permanencia de 48 h 37 min de la levadura BHu9, concentración inicial de 4,98 x 106 cel/mL y una temperatura de inicio de fermentación de 24,68 °C. Para BCm71/BSc114: tiempo de permanencia de BCm71 fue de 24h 15 min, concentración inicial de 2,72 x 106 cel /mL y una temperatura de inicio de fermentación de 24,94 °C. En ambos casos luego de transcurrido el tiempo de permanencia de la levadura NS, BSc114 fue inoculada en una concentración de 2 x 106 cel/ml para finalizar la fermentación. En los ensayos de validación, en el mosto ésteril, ambas co-inoculaciones presentaron menor conentración de etanol comparado con el tratamiento control (p < 0,05). Mientras que en mosto fresco sólo el co-inóculo BHu9/BSc114 registró menor graduación alcohólica comparada con BSc114 y BCm71/BSc114. Descriptores sensoriales tales como amargo, astringencia, calor estuvieron asociados a los vinos con mayor concentración alcohólica. Descriptores frutales se asociaron a los tratmientos con co-inoculación y menor graduación alcohólica. Los vinos obtenidos a partir del cultivo BHu9/BSc114 presentaron asocicación con atributos como tipicidad varietal y matiz rojo. A partir de este trabajo se concluye que la reducción de etanol en vinos empleando co-inoculos de levaduras NS/ S. cerevisiae, previa optimización de factores fermentativos, es una herramienta útil para incorporar a la industria vitivinícola. La estrategia de inoculación BHu9/BSc114 presentó características destacadas desde el punto de vista organoléptico y de la recucción alcohólica.Fil: Mestre Furlani, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza - San Juan; Argentin

Culture-dependent and independent techniques to monitor yeast species during cold soak carried out at different temperatures in winemaking

Transformation of grape must into wine is a process that may vary according to the consumers' requirements. Application of cold soak prior to alcoholic fermentation is a common practice in cellars in order to enhance flavor complexity and extraction of phenolic compounds. However, the effect of this step on wine yeast microbiota is not well-known. The current study simultaneously analyzed the effect of different cold soak temperatures on the microbiological population throughout the process and the use of culture-dependent and independent techniques to study this yeast ecology. The temperatures assayed were those normally applied in wineries: 2.5, 8 and 12 °C. PCR-DGGE allowed detection of the most representative species such as Hanseniaspora uvarum, Starmerella bacillaris and Saccharomyces cerevisiae. As could be expected, highest diversity indices were obtained at the beginning of each process, and survival of H. uvarum or S. bacillaris depended on the temperature. Our results are in agreement with those obtained with culture independent methods, but qPCR showed higher precision and a different behavior was observed for each yeast species and at each temperature assayed. Comparison of both culture-independent techniques can provide a general overview of the whole process, although DGGE does not reveal the diversity expected due to the reported problems with the sensitivity of this technique.Fil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Toro, Maria Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteve Zarzoso, Braulio. Universitat Rovira I Virgili; Españ

Optimization of fermentation-relevant factors: A strategy to reduce ethanol in red wine by sequential culture of native yeasts

Current consumer preferences are determined by well-structured, full-bodied wines with a rich flavor and with reduced alcohol levels. One of the strategies for obtaining wines with reduced ethanol content is sequential inoculation of non-Saccharomyces and Saccharomyces cerevisiae yeasts. However, different factors affect the production of metabolites like ethanol, glycerol and acetic acid by inoculated yeasts. In order to obtain low alcohol wines without quality loss, the aims of our study were: i) to determine optimum conditions (fermentation temperature and time of permanence and initial inoculum size of the non-Saccharomyces population at the beginning of the process, prior to inoculation with S. cerevisiae); ii) to validate the optimized factors; and iii) to assess sensory quality of the wines obtained after validation. Two combinations of yeasts were used in this study: Hanseniaspora uvarum BHu9/S. cerevisiae BSc114 and Candida membranaefaciens BCm71/S. cerevisiae BSc114. Optimization of three fermentation factors that affect to non-Saccharomyces yeasts prior to S. cerevisiae inoculation was carried out using a Box-Behnken experimental design. Applying the models constructed by Response Surface Methodology, the lowest ethanol production by H. uvarum BHu9/S. cerevisiae BSc114 coculture was obtained when H. uvarum BHu9 was inoculated 48 h 37 min prior to S. cerevisiae inoculation, at a fermentation temperature of 25 °C and at an initial inoculum size of 5 × 106 cells/mL. Lowest alcohol production with C. membranaefaciens BCm71/S. cerevisiae BSc114 was observed when C. membranaefaciens BCm71 was inoculated 24 h 15 min prior to S. cerevisiae at a fermentation temperature of 24.94 °C and at an initial inoculum size of 2.72 × 106 cells/mL. The optimized conditions of the two co-cultures were subsequently submitted to labscale validation. Both proposed strategies yielded ethanol levels that were significantly lower than control cultures (S. cerevisiae). Wines fermented with non-Saccharomyces/Saccharomyces co-cultures under optimized conditions were also associated with higher aromatic complexity characterized by the presence of red fruit aromas, whereas wines obtained with S. cerevisiae BSc114 were described by parameters linked with high ethanol levels.Fil: Maturano, Yolanda Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mestre Furlani, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Kuchen, Benjamín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Toro, Maria Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Mercado, Laura Analia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Combina, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentin

Yeast population dynamics during prefermentative cold soak of Cabernet Sauvignon and Malbec wines

Prefermentative cold soak is a widely used technique in red wine production, but the impact on the development of native yeast species is hardly described. The aim of this work was to analyse the dynamics and diversity of yeast populations during prefermentative cold soak in red wines. Three different temperatures (14 ± 1 °C; 8 ± 1 °C and 2.5 ± 1 °C) were used for prefermentative cold soak in Cabernet Sauvignon and Malbec grape musts. Saccharomyces and non-Saccharomyces populations during cold soak and alcoholic fermentation were analysed. In addition, the impact on chemical and sensory properties of the wines was examined. Yeast dynamics during prefermentative cold soak were temperature dependent. At 14 ± 1 °C, the total yeast population progressively increased throughout the cold soak period. Conversely, at 2.5 ± 1 °C, the yeast populations maintained stable during the same period. Prefermentative cold soak conducted at 14 ± 1 °C favoured development of Hanseniospora uvarum and Candida zemplinina, whereas cold soak conducted at 8 ± 1 °C favoured growth of Saccharomyces cerevisiae. At 2.5 ± 1 °C, no changes in yeast species were recorded. Acidity and bitterness, two sensory descriptors, appear to be related to wines produced with prefermentative cold soak carried out at 14 ± 1 °C. This fact could be associated with the increase in non-Saccharomyces during the prefermentation stage. Our results emphasise the importance of the temperature as a determinant factor to allow an increase in non-Saccharomyces population during prefermentative cold soak and consequently to modify sensorial attributes of wines as well as their sensorial impact.EEA MendozaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mestre Furlani, Maria Victoria. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Esteve Zarzoso, Braulio. Universitat Rovira i Virgili. Facultat d’ Enologia. Departament de Bioquímica i Biotecnologia, Biotecnologia Enològica; EspañaFil: Nally, María Cristina. Universidad Nacional de San Juan. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lerena, María Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Toro, María Eugenia. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Instituto de Biotecnología; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Inoculation strategies to improve persistence and implantation of commercial S. cerevisiae strains in red wines produced with prefermentative cold soak

Prefermentative cold soak is a winemaking technique aimed at enhancing aroma and colour extraction in red wines. This study aimed at evaluating implantation and persistence rates of commercial active dry yeast strains (ADY) in wines produced with cold soak using two different inoculation strategies. Cold soak was conducted at 4 ± 1 °C, 8 ± 1 °C and 12 ± 1 °C for 7 days. Two yeast strains (Lalvin ICV D254 and Lalvin Rhône 2056) were inoculated before and after cold soak. Implantation of Lalvin ICV D254 at the end of cold soak was higher when conducted at 8 °C and 4 °C, whereas it was undetectable (<5%) at 12 °C. Lalvin Rhône 2056 showed implantation percentages at the end of cold soak ranging from 40% to 100%, with higher percentages in cold soak conducted at 12 °C. Moderate persistence of ADY at the end of alcoholic fermentation was observed in all treatment inoculated before cold soak. In the treatments inoculated after cold soak, the persistence of Lalvin ICV D254 ranged from 12 to 38% whereas Lalvin Rhône 2056 was less than 5% at the end of alcoholic fermentation. Overall, persistence of both strains improved in inoculation before cold soak relative to inoculation after cold soak.Fil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Lerena, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Casassa, Luis Federico. California Polytechnic State University; Estados UnidosFil: Toro, Maria Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Mercado, Laura Analia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin

Valorization of olive tree pruning: Application for energy storage and biofuel production

This work addresses the valorization and integral use of an abundant agro-industrial waste in sustainable production routes. Olive tree pruning residues were used to obtain bioethanol and activated carbon. This was latter applied to supercapacitor electrodes preparation and also as a detoxifying agent. On the bioethanol route, the residue was pretreated with lime, hydrolyzed and subsequently fermented with native yeasts. The maximum ethanol concentration was obtained by Candida sake BCs88 (3.3 g/l). Prior to fermentation, the liquor was detoxified with activated carbon, achieving removal percentages of inhibitor compounds of 89.2 %, 32.6 % and 91.8 % for polyphenols, hydroxymethylfurfural and furfural, respectively. Detoxification stage improved markedly the performance of all yeasts. KOH was used to obtain the activated carbon, reaching a BET surface of 4083 m2/g. It was applied as supercapacitor electrode generating a high specific capacitance of 264.38 F/g at a current density of 0.5 A/g, and delivering elevated values of energy density (17.83 Wh/kg) and power density (65 W/kg).Fil: Mamaní, Arminda Noemí. Universidad Nacional de San Juan. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mestre Furlani, María Victoria. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Montoro, Maria Laura. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Gassa, Liliana Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Deiana, Ana Cristina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Ingeniería Química. Area Fisico Química; ArgentinaFil: Sardella, Maria Fabiana. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Ingeniería Química. Area Fisico Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentin

Yeast population dynamics during prefermentative cold soak of Cabernet Sauvignon and Malbec wines

Prefermentative cold soak is a widely used technique in red wine production, but the impact on the development of native yeast species is hardly described. The aim of this work was to analyse the dynamics and diversity of yeast populations during prefermentative cold soak in red wines. Three different temperatures (14. ±. 1. °C; 8. ±. 1. °C and 2.5. ±. 1. °C) were used for prefermentative cold soak in Cabernet Sauvignon and Malbec grape musts. Saccharomyces and non-. Saccharomyces populations during cold soak and alcoholic fermentation were analysed. In addition, the impact on chemical and sensory properties of the wines was examined. Yeast dynamics during prefermentative cold soak were temperature dependent. At 14. ±. 1. °C, the total yeast population progressively increased throughout the cold soak period. Conversely, at 2.5. ±. 1. °C, the yeast populations maintained stable during the same period. Prefermentative cold soak conducted at 14. ±. 1. °C favoured development of Hanseniospora uvarum and Candida zemplinina, whereas cold soak conducted at 8. ±. 1. °C favoured growth of Saccharomyces cerevisiae. At 2.5. ±. 1. °C, no changes in yeast species were recorded. Acidity and bitterness, two sensory descriptors, appear to be related to wines produced with prefermentative cold soak carried out at 14. ±. 1. °C. This fact could be associated with the increase in non-. Saccharomyces during the prefermentation stage. Our results emphasise the importance of the temperature as a determinant factor to allow an increase in non-. Saccharomyces population during prefermentative cold soak and consequently to modify sensorial attributes of wines as well as their sensorial impact.Fil: Maturano, Yolanda Paola. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mestre Furlani, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Esteve Zarzoso, Braulio. Universitat Rovira I Virgili; EspañaFil: Nally, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; Argentina. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; ArgentinaFil: Lerena, Maria Cecilia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza. Centro de Estudios Enológicos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Toro, Maria Eugenia. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Vazquez, Fabio. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Combina, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza. Centro de Estudios Enológicos; Argentin