Turning electricity into food?
Did you know that it is possible to transform carbon dioxide and electricity into cattle feed and food for humans? Because it is.
Using renewable electricity and carbon dioxide extracted from air, microbes can be used to produce a single cell protein that is over 50% protein and 25% carbohydrates, with the remaining part being fatty substances and nucleic acids. The research conducted jointly by LUT and VTT Technical Research Centre has already been able to produce the first food ingredients in the laboratory.
"Yeast is no more extraordinary than our ingredient; yeast is also a microbe," says head of the research, LUT Professor Jero Ahola.
The method is based on growing microbes, i.e. micro-organisms. The invention is not a new one: the method has been previously used to manufacture products such as the Torula yeast and the Pekilo protein. The new aspect in the researched method is using renewable energy. The energy fed to the microbes is solar and wind power. In addition, the carbon used as the building material of the microbes is extracted from air with carbon dioxide recovery.
"We are developing more methods to adjust the growth process so that the microbes can grow as well as possible," says Ahola.
Deep in a vat
Growing single cell proteins is done in a bioreactor, which is a device that sustains the operative conditions of a biological process. In practice, a bioreactor can be the same kind of vat that is used in brewing beer, for example.
Renewable electricity is conducted to the bioreactor. The produced current breaks water into hydrogen and oxygen. At the same time, carbon dioxide extracted from air is introduced into the reactor. Carbon is one of the most important raw materials for growing microbes. Other necessary raw materials are nitrogen, phosphorous, potassium, and the micronutrients and salts required by cells.
When the microbes in the reactor receive the nutrients that they need, the cell mass grows and multiplies. Before use, the mass is filtered, treated with ultra-high temperature processing and then dried. The result is a mixture that resembles protein powder or dry yeast. The idea is that in the long run, it could be used in cooking without any further processing.
"We still need to do a lot of testing before the product can be used as food for animals or people. The framework is pretty strict," commented researcher Juha-Pekka Pitkänen from VTT.
Alternatives to the table
Right now, the manufacturing process takes about two weeks. For the product to be competitive, the production time needs to be shorter. Extensive commercialisation is still far from reality, and in the initial stage, the researchers are focusing on producing a mixture intended as cattle feed.
The researchers estimate that the method could be used to replace some of agricultural food production. Globally, agriculture is the second largest producer of greenhouse gases, the largest being the energy sector. There is only a limited amount of agricultural land, so more farmland is being created by clearing forests, which in turn causes more greenhouse gas emissions. At the same time, the world's population is increasing, as is the need for growing more food. The method being researched could be used to produce protein-rich nutrition without breeding cattle or using farmland, eliminating emissions.
"Compared to the competing product, soy protein, the difference is clear. You need sunlight, moisture, soil and a specific temperature to grow soy protein. This means that the environment has to provide the right kind of conditions, and then the soy still needs to be shipped to Finland. The method we are researching completely separates the manufacturing process from the environment, and in an environmentally friendly way, too," explains Ahola.