Seed World

Researchers Close to Utilizing Rapeseed For Human Consumption

In the EU, half of plant proteins come from rapeseed plants. The plant has only previously been used for oil and animal feed due to its unsafe and bitter nature for human consumption. A new study from the University of Copenhagen was published in Nature where researchers have said they are getting closer to removing the plant’s bitter substances. This will create a new protein source that helps work toward the green transition according to a release.

Rapeseed is currently cultivated for edible and industrial oils and as a protein supplement for animal feed. The benefits to the plant being bitter is a defensive mechanism to disease and herbivore pests, but the downfall is it is not edible for humans.

The researchers from the University of Copenhagen’s Department of Plant and Environmental Sciences were able to identify the proteins that help to store the bitter substances in the seeds of the thale cress plant. Thale cress is used as a model since it is a close relative of rapeseed.

The research can be used to remove the bitter proteins which would as a result make the rapeseed not bitter.

“The climate crisis demands that we reduce meat consumption and eat more plants, which is where rapeseed has great potential as a new source of plant protein in the green transition,” said Professor Barbara Ann Halkier, research lead. “Our latest research results bring us a critical step closer to making full use of rapeseed.”

The bitter substance in rapeseed is called glucosinolates and it also makes up the spicy flavor in wasabi and mustard. The rapeseed cake, which is what remains after the oil is removed can only be used in limited quantities in pig and chicken feed because of this bitterness even though its protein content is between 30 and 40 per cent. While some glucosinolates are healthy, those found in rapeseed are not.

“Our research demonstrates that the connection — a kind of umbilical cord — that exists between the seeds and surrounding fruit shell, is a cell factory for the production of glucosinolates which end up in the seeds,” said Dr. Deyang Xu, lead author of the study. “After all, plants are well rooted in soil and cannot just walk away when there is danger. They need to produce a multitude of defensive substances to protect themselves from attacks by disease and herbivores. Our discovery has allowed us to find a way to eliminate these bitter substances from the seeds.”

“The next task is to show that we can transfer our result from Arabidopsis to the closely related rapeseed plant, which we are now working on,” added Dr. Xu.

The research was done because of a 10-year grant from the Danish National Research Foundation to the DynaMo Centre at the Faculty of Science’s Department of Plant and Environmental Sciences.

“I cannot stress enough how important this long-term grant has been for us to be able to land this major research result,” said Barbara Ann Halkier. “It has really given us time to immerse ourselves in the details and geek out, which has paid off.”

Read the full Peer-Reviewed Publication.