Researchers at the University of Copenhagen will study what plants do when they need to mobilize and use their seed proteins to germinate. If successful, they could potentially discover a more sustainable method of extracting food protein from plants using enzymes.
Protein from pea, bean and lentil seeds are good alternatives to meat, as they contain up to 40% protein. This is one of the reasons Poul Erik Jensen, professor in the Department of Food Sciences at the University of Copenhagen (UCPH FOOD), sees great potential in determining how best to use enzymes to extract seed proteins. Researchers are using pea seeds as a prototype.
“I see a lot of potential that we can use enzymes to extract proteins from the seeds of plants and develop them so that they can replace the less sustainable methods used today. At the same time, we hope to be able to increase the digestibility of vegetable proteins and thus create a method that can be implemented in sustainable and healthier food production, ”explains Poul Erik Jensen.
Today, proteins are often extracted from plants by “wet” processing, using water and chemicals.
“You first use a chemical solution in high pH water to extract the proteins, and then you collect them in a low pH solution, after which the material has to be dried. It is a heavy processing method because it requires water, time and a lot of energy, ”explains Poul Erik Jensen.
You can also choose a mechanical processing method, where you turn the dry peas into flour.
“But proteins are partially destroyed / modified by mechanical and wet processing methods, in the sense that they open up in different ways, which can affect functionality both negatively and positively. This has an impact on the sustainability of the processing as well as on the nutrition we get from the proteins, ”explains Poul Erik Jensen.
How does the plant mobilize and use its own proteins?
In the project, the researchers ask a key question:
“If the pea seed were to germinate, what would it do to mobilize the protein from the seed?” We would really like an answer to that, ”says Poul Erik Jensen.
The hypothesis is that plants, including pea seeds, are predisposed to extract the best possible nutrition from protein using their own natural method. This is basically what we want when we use protein for food – both for climatic and health reasons.
“If we know if there is a certain combination of enzymes that help soften the seed and release the protein, we can potentially use these enzymes for a gentler method of extraction than the methods used today,” explains Poul Erik Jensen.
Problem: We need to use less water
The idea is not new, as a similar method has been used in the bioethanol industry, where straw has been broken down and cellulose has been used as a substrate for cellulose degrading enzymes.
“This method is at the origin of all the thinking on bioethanol which has been very popular all over the world. Enzymes are used to cut the cellulose strands and turn them into sugar molecules, which are transformed into bioethanol with the help of yeast, which can then be used as fuel. And it is this reflection that we are going to try to apply to the proteins of the seeds ”, specifies Poul Erik Jensen.
But if we can use it in sustainable food production in the future, we need to use a lot less water in the process, he stresses.
“Traditionally, the process would require a lot of water, but we want to run the enzyme treatment with as little water as possible and make the seeds semi-liquid, like porridge. And if the enzymes are to work in the slurry, we have to move the material, so part of the project is to learn something about enzymatic flow processing, ”explains Poul Erik Jensen.
Therefore, we cannot live by eating untreated plants.
For many years there has been a rather negative perception of “processing” food. And that might be fair enough in some contexts. But Poul Erik Jensen points out that there are also a lot of transformations that result in plant nutrients being made available to us.
“For example, if we eat raw plants, some proteins will not be readily available to us because they are trapped in intact cells surrounded by a cell wall. Here, the proteins are not soluble, so we cannot derive the nutritional benefit that we could have had if they had been transformed ”, explains Poul Erik Jensen and continues:
“In the western world, where people typically eat more than enough calories and protein, it might work well, but it’s not good nutrition for kids or people who have to settle for less food. This is why we cannot base all of our food on plants that are not processed.