It was a nasty day in July. On the road, the car’s windshield wipers were activated at maximum speed but were struggling to evacuate the deluge of rain that was falling on Brittany at that time. Welcome to Pontivy. A few meters after the entrance sign to the small town in Morbihan, I can make out the facade of the IUT. Without doubt one of the smallest in this country with fewer than 200 students enrolled.
Yet it is here, in a laboratory overseen by the University of South Brittany, that an ambitious food innovation project is hidden. A process that appears rather simple but which could revolutionize the valorization of the most “ugly” products by allowing them to be better preserved. The name of this revolution? “Pidospal”. An acronym for this project with the barbaric name: “industrial process for osmotic dehydration of food products”. Not very digestible. And incomprehensible for all the non-specialists that we are. Let me (try to) explain it to you.
The taste of onion remains in the mouth…
On the lab bench, colored strips are arranged. At first glance, they look like Hollywood brand chewing gum. The posters placed next to them indicate the flavors and seem to confirm our impression of a candy: kiwi, strawberry, banana. OK, that fits. The rest is a little stranger: tomato, cucumber and even onion. Clearly, this is not chewing gum. These colored bars are in fact the results of dehydration. Dehydration by osmosis.
This natural diffusion mechanism allows water to be evacuated from a product through a membrane when it is immersed in a solution. For this experiment conducted at the IUT of Pontivy, we will only know that the recipe for the solution is composed of water, salt and sugar. By immersing pieces of tomatoes, cucumbers or onions previously wrapped in a pouch in this solution, we can quickly evacuate 90% of the water from a fruit or vegetable. And this, without any recourse to an energy source, or almost.
“Everything is imaginable”
Food dehydration is usually done either by steam or by heating the products. A process that has two drawbacks: it is energy-intensive and can alter the nutritional qualities of a tomato or a banana. The interest of osmosis is obvious. “By reducing humidity, we greatly increase the shelf life of food,” assures Yasmine Autem, engineer of the research unit. “Since we work at room temperature, we consume very little energy. Here, we do not completely dehydrate, in order to keep a soft material. We can do it with fruits, vegetables, but also dairy products, fish. Anything is imaginable,” adds her colleague Marie Furic.
In the minds of these researchers, the idea is to seduce manufacturers with a more economical and environmentally friendly technique, while avoiding waste. “It’s an idea to enhance damaged or uncalibrated products. We can imagine finding them in sandwiches, puff pastries or rolls. Because the taste remains unchanged,” assures Elouan Bioret, an engineering student who is also following the project. We were able to test the samples produced and it is true that for certain products such as cucumber, strawberry but especially onion, the taste remains pronounced (and for the onion, know that it stayed in the mouth for a while). For others, the result is disappointing. “Banana, it looks a bit like andouille. But the taste is not there,” regrets a cook present at my side.
Dried meat already sold in supermarkets
To carry out their tests, the researchers formed a partnership with the company CIP Automation. Specializing in robotization, the company has developed an experimental line to manage the osmosis of a product from A to Z. A process called “Osmofood” that CIP Automation has already sold to Cooperl. For several years now, the pork giant in France has been offering dried pork matches under its “Montagne noire” brand. “The use-by date has been extended. And above all, they can valorize by-products that they didn’t know what to do with,” argues Guillaume Brien, sales manager at CIP Automation, a subsidiary of the Ovalt group.
Faced with soaring energy costs, the osmosis dehydration process is obviously of interest to food industry manufacturers, of whom there are many around Pontivy and in Brittany. Sales Manager at AlgoleskoDavid Lecouze knows how interesting this technique is for his company specializing in algae. “Algae are 98% water. So you can imagine that if we find a way to dehydrate them at a lower cost, we’ll be interested.” But he’s temporizing. “It’s an innovative project, but it’s still too early to talk about it.” Understand: the technique is not yet mature. But it’s being looked at very, very closely.