Anyone knows that acorns are one of the favorite foods of pigs or that squirrels hide them to survive the winter. Perhaps they are also produced by holm oaks, cork oaks and other trees of the Quercus family. But little more. What is much less known is that this fruit is rich in compounds such as GABA (gamma-aminobutyric acid) and can have applications in nutrition, cosmetics or even pharmacy.
The acorn, however, keeps few secrets for researchers like Inmaculada Hernández, from the In vitro plant cultivation group of the Madrid Institute of Rural, Agrarian and Food Research and Development (IMIDRA). In their laboratories they have been working for five years on a line of research called LABellota, which has given rise to a patent for the production of “laboratory acorns” from plant tissues.
An experience of 30 years
Work with species of the Quercus family is not new at the institute. For more than 30 years, different teams have investigated the genetic improvement and conservation of these trees. These efforts have been key to select specimens more resistant to diseases such as dry, a process of forest decay that causes slow growth, scarce or chlorotic leaves and premature fall of foliage and that is affecting these species. «We are dedicated to the in vitro cultivation of plants, especially forest species. We clone individuals that stand out for some characteristic, such as resistance to drought or diseases,” explains Hernández.
For this they use somatic embryogenesis, a method that allows embryos to be generated from tree tissues, such as leaves. The process consists of inducing, under controlled laboratory conditions, the formation of plant embryos that are genetically identical to the original tree. «In the case of the cork oak, we start from leaves and obtain embryos that, in reality, are like acorns without a cover. It is, to understand us, as if we peeled the acorn. From them a new identical plant can be developed,” details the researcher. The entire process is carried out under sterile conditions, in closed containers that contain a culture medium with the necessary nutrients. In these chambers light, temperature and humidity are controlled, which pIt allows the production of plant material throughout the year. Furthermore, embryos have the ability to multiply, which makes it easy to obtain large quantities in a short time.
For years, the main objective was the propagation of selected trees. However, some time ago the team decided to explore a new avenue: take advantage of these “acorns” for uses other than reforestation. “We knew that this fruit is a very interesting food from a nutritional point of view, so we decided to analyze whether these embryos had a similar composition,” explains Hernández.
Scaling
That was the origin of a second line of work that has culminated in this patent for a “procedure to obtain biomass with added value from these crops.” Modifying the cultivation conditions, such as the type of media or the use of bioreactors, researchers can direct the development of embryos. In the first stages of development, these in vitro acorns have a high protein content and, especially, GABA, an amino acid with beneficial effects on health. This compound acts as a neurotransmitter and is associated with relaxing and calming properties, which is why it is already used as a supplement in animal feed. In more advanced stages of the embryos, structures similar to immature acorns are obtained, rich in polyphenols, compounds with high antioxidant power. “These compounds are of great interest to both the food, cosmetics and pharmaceutical industries”comments Hernández.
Although they are currently working at a laboratory level, they are already working to find industrial partners who want to develop this technology on a larger scale and thus explore its commercial use for feed additives or in the pharmaceutical industry, etc.