Duckweed, a sustainably cultivated plant also known as water lentils, has been officially approved for consumption within the EU by the European Food Safety Authority (EFSA).
Water lentils are widely consumed in some Asian countries, but have not yet become a food staple in the West. However, this may be about to change, thanks in large part to the work of Ingrid van der Meer of Wageningen University & Research in the Netherlands.
Van der Meer, a senior researcher and head of the Bioscience department at Wageningen Plant Research, first became interested in water lentils ten years ago. She was struck by the sustainability of their production; the plants can produce over six times as much protein per hectare as soy and each one divides into two every three days, allowing for exponential growth.
“They are an exceptionally sustainable vegetable,” says van der Meer. “They are cultivated on water and don’t need many nutrients. Of course, water is a precious commodity, but in a simple greenhouse or vertical farm, growers have the ability to employ this very efficiently.”
Cultivation and marketing
The type of duckweed consumed in Thailand was approved by the EU in 2021, since it is a traditional food from another country. However, lemna — the variety being researched by WUR — is considered a “novel food” not commonly consumed by humans, and had to undergo a rigorous process to be approved.
Water lentils are not currently cultivated commercially within the EU, but WUR is involved in a project that aims to produce them sustainably, safely, and hygienically through methods such as vertical farming. Researchers suggest the vegetable could be marketed in many forms, including fresh, frozen, ready-made, or as a protein additive, including in meat alternatives.
When will water lentils be available?
Taste panels have reportedly responded positively to dishes made with water lentils, which are described as having a “plant-like, slightly nutty flavour and a nice bite”. However, it may be some time before the vegetable arrives on supermarket shelves, since food companies will need to be convinced that there is a market for it.
Elsewhere in the world, US company Plantible Foods is working to extract protein from lemna for functionalities such as gelling, binding, emulsification, and solubility. The company recently raised $30 million to scale its operations, claiming it was seeing “insatiable” demand for duckweed-derived ingredients. The protein has GRAS (Generally Recognized as Safe) status in the US.
“[Water lentils] have a number of biological processes that differ from those of other plants,” says van der Meer. “From a scientific point of view, water lentils are very intriguing. They grow quickly, are suitable for contained cultivation and their dry weight contains massive amounts of protein. I thought: why don’t we eat this?”
