06/A235
Aislamiento, selección y multiplicación comercial de levaduras vínicas autóctonas, de las regiones vitivinícolas de la provincia de Mendoza. 2ª etapa: departamento de Junín
Isolation, selection and commercial multiplication of autochthonous yeasts coming from different zones of the province of Mendoza. 2th stage Junín zone
Director: FORMENTO, Juan Carlos
E-mail: jformento@fca.uncu.edu.ar
Co-Director: ERCOLI, Eduardo; DIAZ PERALTA, Eduardo A.
Integrantes: SFREDDO, Elisabeth; NAZRALA, Jorge; PALADINO, Silvia; GALIOTTI, Hugo; LUQUEZ, Claudia Victoria; SÁNCHEZ, Laura; MAZA, Marcos; BIERE, Carlos; GENOVART, Javier; ROMMY RIVEROS; BENVENUTTI, Andrés; SCANIO, Cayetano
Resumen Técnico
La tipicidad y el carácter de los vinos se sustenta, entre otras cosas, en el conocimiento y caracterización de las levaduras autóctonas de la zona de la cual provienen sus uvas..
El objetivo de este proyecto es el aislamiento, selección y multiplicación de levaduras autóctonas de los viñedos de cada una de las zonas vitivinícolas de Mendoza, realizándose en esta etapa, en el departamentos de Junín. Se ha realizado anteriormente esta tarea en los departamentos de Luján de Cuyo y de Maipú, resultando seleccionadas tres cepas de levaduras, una de las cuales( FCA 32) llegó a ser producida comercialmente, en el primero y dos preseleccionadas en el segundo.
El aislamiento de levaduras se realizará durante el verano a partir de muestras de uvas extraídas de diferentes viñedos, mientras que durante la época invernal las muestras serán extraídas del suelo y de restos de racimos secos. Las levaduras aisladas serán seleccionadas por sus características fundamentales mediante estudios microbiológicos, para luego realizar una segunda selección evaluando sus características enológicas a través de microvinificaciones.
Posteriormente con las levaduras ya seleccionadas se realizarán vinificaciones a nivel piloto. Las cepas que se distingan durante esta etapa serán sometidas a ensayos a escala semi – industrial e industrial para confirmar las cualidades destacadas de las mismas.
Las levaduras finalmente seleccionadas serán probadas en cuanto a la resistencia al proceso de multiplicación industrial y de secado y serán nuevamente contrastadas en su aptitud enológica a nivel piloto. Las cepas capaces de superar esta etapa serán producidas en pequeña escala y distribuidas en bodegas interesadas de la zona para su ensayo y evaluación final a nivel industrial. De acuerdo a los resultados que se obtengan, se industrializarán las mejor calificadas y se comercializarán.
Summary
Formulation and basis reasons of the problem to investigate.
The object of this work is the isolation, selection and multiplication of autochthonous yeasts coming from different zones of the province of Mendoza to destine them to the elaboration of wines. Once achieved the selection, it proposes to elaborate yeasts as commercial product that satisfies the needs of the regional market.
This study arises as a need to satisfying, since sufficient studies do not exist on the native yeast in the province of Mendoza. The employment of selected yeasts helps to obtain wines of high quality, due to the fact that the fermentation begin rapidly, avoiding the action of the bacteria in the initial stages of this process, which generate high contents of volatile acidity. The selected yeasts tolerate high concentrations of alcohol, ferment with rapidity, taking the wines to dryness. From a flavor point of view, they have a behavior predictable, originating an agreeable product and without faults. But, though there exists the need of the employment of selected yeasts, in the present circumstances, its utilization is limited due to its cost, for being products imported, whose price of sale changes with the dollar and the Euro. The national production of this winemaking input would improve its differential qualities on the global market and would help to diminish the cost of production of our wines, as well as also to offer an exportable product to other wine zones of the world.
The selection of yeasts will be made from the native yeasts; during the summer from samples of grapes extracted from different vineyards and vines, and during winter period, the samples will be extracted from soil and remains of dry clusters. The way of selection will be analogous to the wine, using concentrations of SO2 of 100 ppm and concentrations of alcohol of 12 %, in order to rescue the microorganisms capable of supporting the habitual conditions of winemaking.
The criteria of selection to using in this work are: resistance to 12 % of alcohol concentration, resistance to a concentration of 100 ppm of SO2, speed of fermentation, production of agreeable aromas, rapid sedimentation once finished the fermentation and minimal production of acids.
The final aim is the commercial production of the yeasts. This would help to be an economical benefit to the industry been interested in this product, since the costs of production of these yeasts will be minor that those of the yeasts that are available on our market, nowadays. The dry active yeasts are imported products, and they are sell at US$ 50 for 500 g.
Besides the search of new yeasts in a new region, the work consist in the multiplication as a pilot of the best already selected yeasts. It will be studied their kinetic to define the ideal parameters of substratum, pH, temperature and level of oxygen for make, in a following stage and depending on being able to put in functioning a reactor of 1000 liters, a semi - industrial multiplication.
Objectives.
General: isolation, selection and multiplication of the autochthonous, typical and predominant yeasts in the studied zones, whose excellent winemaking qualities are expressed in the quality and tasting characteristics of the elaborated wines.
Specifics:
- To isolate yeast Saccharomyces cerevisiae.
- Make a previous selection of whose have winemaking aptitude.
- To define the parameters of multiplication of the selected yeast.
- To multiply industrially the selected yeasts and commercialize them.
- To preserve the yeast in the regional pull of yeasts of the Microbiology Department.
- To quantify the distribution of yeasts in different organs of the plant of grapevine in different growing season states.