Speaking of duckweed, most people may think of an unsightly green film growing on the surface of a stinking, stagnant pool of water. However, this protein-rich plant may soon be on your dinner table, as Europe has approved the plant for human consumption.
Locally grown duckweed (aka "water lentils") has long been available in food markets in Thailand and other Southeast Asian countries. However, this is certainly not the case in Europe, North America and other parts of the Western world, where duckweed is often grown simply as a biofuel source.
About a decade ago, Dr. Ingridvander Meer and colleagues at Wageningen University in the Netherlands set out to change that. Their efforts have now paid off as they convinced the European Food Safety Authority (EFSA) that a species of duckweed known as "Lemna" is safe for human consumption.
The European Food Safety Authority has therefore approved the marketing of Lemna as a vegetable in continental Europe. In fact, the organization approved the sale of Wolffia-type duckweed four years ago, which brings us to another water lentil-related challenge... getting people to actually buy and eat the stuff.
As a cash crop, water lentils actually do have some big selling points. First, they are considered a highly nutritious "superfood," containing about 35% carbohydrates, 20% minerals, and up to 40% protein. They also don’t require pesticides and fertilizers, don’t compete with other crops for farmland, and can be grown sustainably in shallow pans of purified water in greenhouses or vertical farms, meaning they can even be grown in cities. Not only that, but they grow very quickly.
"Lentils grow much like yeast," says VenderMeer. "The plant divides into two plants every three days. Then the plants divide into four plants and continue to grow exponentially. To ensure a good yield, they need to be harvested once or twice a week."
In a series of taste tests involving more than 1,000 volunteers, Lemna lentils were served to participants as an ingredient in dishes including soups, stews, quiches and risotto. After initially adjusting to the flavor, which some described as "nutty," testers generally agreed that lentils were comparable to spinach in both flavor and palatability.
Like spinach, lentils are also available in fresh or frozen form. Still, we’ll have to wait and see how long it will be before lentils appear in a supermarket near you.
"At Wageningen we have a wealth of knowledge in growing and product development, but we are also researchers," says VenderMeer. "Now, water lentils need to be recognized by the food industry so that consumers can buy and use products containing water lentils."