Text written in Basque and translated automatically by Elia without any subsequent editing. SEE ORIGINAL

From the oven to the lab

Yeast cells are intended to be microencapsulated and released and activated only at a certain temperature. It uses a cold day.

Onion, dried fruit, with raisins, nothing, whole flour, baked in wood..., there are dozens of types of bread. But everyone needs at least bread flour, water and yeast. Without yeast there is no bread. It has been in use for thousands of years, but it is also the time of new technologies.

Unleavened bread, if there are. The most popular example is the cake, which is made from corn flour. But everyone we know in the form of bread has yeast. Yeast is a fungus that feeds on flour, while the bread becomes fluffy. This is called fermentation.

Fermentation is a process that needs to be well controlled if good bread is to be obtained. And if you want to store the product for a long time, you also have to stop the fermentation. Refrigerators are used today.

However, the Artepan bakeries in Vitoria-Gasteiz want to change this; they want to find another way to stop the fermentation in order to avoid freezing and gain time.

TXEMA PASCUAL, ARTEPAN: It is what is usually done, freezing the pieces after they have been shaped. Then, when it is desired to obtain the final product, what must be done is to thaw it, carry out the fermentation and put it in the oven. In some cases, what they need is to shorten that time. So what we're trying to do is, we're going to do fermentation in the oven itself.

Artepans turned to the LEIA research center for solutions. At LEIA they carry out studies on food conservation, among others. They started working on a very specific idea.

LEIRE ARROYO DUA, LEIA: The LEIA plating solution consists of microencapsulation and immobilization of yeasts in said microcapsule. Microcapsules are microspheres in which the yeast is isolated and protected from the outside.

Yeast cells, if isolated from the dough, cannot access the flour that is their food, i.e. they cannot ferment the bread dough. Therefore, there is no need to freeze the dough.

To make microcapsules, yeast cells are mixed with gelatin and/or waxes, after which the mixture is taken out of a small faucet and passed through a wheel with sharp blades instead of spokes. When the blades cut the faucet, microscopic droplets are formed; these are microcapsules containing yeast cells. But, the microcapsules are so small that stroboscopic light is required if they are to be seen.

At a glance the technology seems quite simple, but there are many factors to consider.

LEIRE ARROYO DUA, LEIA: The disc from which the capsules are obtained must have an exact speed; the material must in fact be subjected to a pressure to exit the mouth of the tube; the material must exit the mouth of the tube at a precise temperature; on the other hand the choice of yeasts, because yeasts are living microorganisms, and it is difficult to choose one or the other; etc.

Gelatins and waxes are used in the manufacture of microcapsules. These two components are solid at room temperature and therefore the mixing is carried out hot. The machine’s faucet itself should also be hot so that the mixture does not solidify immediately after it exits.

Upon reaching the cutting tool, the tool cuts and, being liquid, the pieces assume a spherical shape and completely surround the yeast cells. It is important that no yeast remains on the outside of the drop, so that it is in contact with the paste and does not occur during fermentation.

The drop, in the lower path, falls into the container and solidifies. And then they'll filter them out so they're ready to use. They
have already succeeded in making microcapsules of both shape and appropriate size. But in the end, the time will come to bake the dough and make the bread.

LEIRE ARROYO DUA, LEIA: When the bread dough is in the oven, as the temperature increases, the material forming the capsule will disintegrate and gradually the yeast will be released and the fermentation will begin inside the oven.

Not only that: each type of bread or candy requires a different temperature in the oven, and in response they will use gelatins and waxes with different melting temperatures.

They are currently in the final phase of the investigation.

TXEMA PASCUAL, ARTEPAN: Right now, I think they're finishing up in the lab, and we'll start doing mass and product testing right away.

One last detail: the gelatins and waxes that are being used will not affect the taste of the bread. That it did you good!