With the yeast not only bread is made ... wine also. But not all yeast is appropriate. We must find those with higher fitness, according to the product you want to achieve.
this is working in a research team of the Universidad Nacional del Comahue (UNCo), led by the teacher Adriana Caballero. The project's objective is to select the best yeast for the production of regional fine wine sensory characteristics, quality-controlled differential. This will give added value to the red wines of the Upper Black River Valley and Neuquén, and improve their ability to compete in the global market. Keep in mind that at present wineries in the region must import the yeast used for fermentation.
To learn more, talked with researchers Adriana Caballero (PhD in Biochemistry) and Marcela Sangorrin (PhD in biology).
What are yeasts?
The vinification process is to tread the grapes, ground or crushed into wine. This transformation is carried out by a living organism called yeast. If this organism is not present, the wort is not transformed into wine.
But in all yeast species, and within the species sacaromisie particular service (with which it is bread, beer and wine), you can select different individuals with better fitness and better able to make certain products. For example, the brewers keep their strains of yeast for beer production. So we're trying to do is select the entire population of yeast indigenous to the area, an individual who meets the best properties. To produce good quality wines and also with different features and properties in the region.
How does the yeast in the process?
The metabolism of the yeast turns the sugar in grape juice (the juice) in ethanol. This is one of the first products we want to have wine. Not only that, also contributes to the body and aroma of wine.
The problem is that not every microorganism used, because it can produce undesirable compounds. So we must select the proper yeast for this region, for certain varietals, and technological conditions of certain wineries. For example, if you want a floral wine, yeasts are more compounds contributing to aroma of flowers. Each gives you a special wine. What
yeast were selected in the region and how this selection of yeast?
We selected two types of yeast: the service and sacarosimietica sacaromisie, that has the ability to enhance the primary aroma.
What is done is to evaluate the different features. For example, to develop well when yeast enters the grape because it makes too much sugar. And from the substrate (the grape) has to develop at some time a large amount of ethanol without producing too much volatile acidity, or other odors. It is important to provide distinctive features like those that make heavier the wine.
"For what type of wine yeast would be obtained?
Especially for the production of young red wines. Because 85% of the production of red wine region and youth. The young wine is one that has no aging in wood or, if any, is short term. In a young wine, it is essential to fermentation aroma that comes from the metabolism of yeast. Because neutral varietal grapes such as those made here, if the merlot or pinot-producing yeast aroma is basically what gives the wine aroma (in other cases the smell also provides the juice and / or aging .) You can also select yeasts that are able to enhance the primary aroma of wine.
What is the process of analysis of yeast?
samples must be taken in various stages of fermentation, and the laboratory are separated all the yeast that are present. By having separate trials may be given a specific, identified to individuals. This can be done with the advent of techniques from molecular biology are also techniques that we use.
And what were the results of tests done with these two types of yeast?
We tested these strains at the industrial level, in the cellars of the region, and have had good results compared with commercial yeasts. The University
have to register yeast, development, and as it happens. We will continue investigating and searching for other alternatives and then a company can spend to produce it.
yeasts being used in the wineries of the region are they? What differences might have our wines with yeast from here? Producers purchase
yeasts that are not in this region but are tested in other wine regions and selected according to a catalog. But this takes away criminality and characteristics to the wines of the region.
Studies made in the various wine regions worldwide, according to which there would be a geographic structure in populations of yeast. That is, each region would yeast populations with specific characteristics that also would be better suited to grape must in each location. Therefore, it would be better able to compete. The important thing is that a yeast is made "famous" for certain properties.
The same goes for the production of vines, geography also affects. A varietal is not given in the same way in one region than another. For example, in the upper valley region is very good at the varietal Merlot. Which does not happen in Mendoza. Do
local businessmen could produce regional yeast?
wine market is quite complicated because there is oversupply. It should be noted in the quality of wines and industry must invest in technology. Within this technology can be an investment in agronomic level, a cellar-level investment, ie everything related to the equipment, and investing primarily in biotechnology, to handle the microorganisms that drive the process of winemaking.
is a low-cost technology compared to the rest, which improves the quality of wines in both large and small enterprises who can not afford to make capital investments in other aspects. The idea has always been our aim to develop a technology that allows the family businesses to earn a better place the quality of their wines according to an investment they can make. It is also a good strategy for the development of certain types of industrial activities in the region and allows small businesses compete against large companies.
What types of producers or winemakers may care about this project?
This development are interesting for everyone. Historically not given importance to the organisms that carry forward the process of making wine, but now with the advancement of knowledge recognizes the value of the process and the need to control.
then able to select these yeasts to control one aspect of the process, the microbiological Today is not controlled.
What is the next step in the selection of yeast?
The next step is to bring engineers and do necessary tests so that they can own tests with industrial production. We also want to test other characteristics of these strains, which may become necessary for which dry yeast and can stay viable.
The implementation of molecular biology techniques for identifying individuals, was also used to transfer the experience of the research group of health workers in public hospitals of the Province of Neuquén, hereinafter will use this methodology in the hospital.
also being created in the Universidad Nacional del Comahue, a pathogenic yeast bank in the region. And another result of the project, having preserved more than a thousand strains of yeasts of this region in the laboratory. That is a gene bank that is the heritage of all the inhabitants of this region and the country, with potential to be applied in other biotechnological developments.
is difficult to price the value of this gene bank because it means preserving our genetic heritage for future generations.
Contact:
Lab
Microbiology and Biotechnology Dept. Chemistry-Faculty of Engineering National University of Comahue
email: msangorr@uncoma.edu.ar
54299 4490300 TE 493 and 287 int
4490385 or 4488306 FAX 54 299
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