Exploring an untapped versatile superfood

Researchers are taking advantage of one of the fastest growing plants on Earth to investigate its potential as a global new food source

Close up of duckweed in its natural water environment

Feeding a growing global population a nutritious, healthy and varied diet is a huge challenge, not least when faced with the stumbling blocks of climate change and economic uncertainty.

But a researcher at Leeds is helping to improve our understanding of a fast-growing plant that just might be part of the answer.

When you think about what you eat, you might believe yourself to have a balanced, varied diet. But in truth, much of our food ultimately derives from a shockingly small number of ingredients, our species having depended on a narrow and unchanged range of crops for centuries.

Because for all the cuisines in the world, all the brands on our shelves and all the progress manufacturers have made with modern factory technologies, it remains the case that 60 per cent of the calories consumed by humans come from just three – yes, three – plants (PDF).

Field being harvested by a combine harvester

A changing planet with a dietary challenge

In developing countries in particular, staple foods are typically rich in starch, but low in proteins and other essential nutrients, contributing to malnutrition.

It’s a dietary problem that’s set to worsen, with predictions that global production of animal protein will slow while meat prices rise, making it yet harder for many to eat healthily.

And even if things change economically and, as generally happens, meat consumption increases alongside incomes in those nations, there are huge environmental concerns, with animal rearing contributing to more than half of the world’s greenhouse gas emissions.

There’s also the challenges of climate change and natural disasters in a world more interconnected than ever, with a 10 per cent increase from 2022 to 2023 in the number of people facing food insecurity due to protracted food shocks and crises.

So what if we could take a plant that grows so it can double its mass in just a few days and turn it into humanity’s first new major crop since the Edwardian era?

It’s an idea that came to Dr Idolo Ifie by accident and has occupied his thoughts ever since.

Duckweed in water with hand lifting some out of water

The superfood you’ve never heard of

The plant in question is duckweed. In fact, that’s not strictly true – it isn’t just one plant after all.

“There’s a huge variety of duckweed species,” Idolo, Lecturer in Food Processing at the University of Leeds explained. “More than 30, in fact.”

But all of them share common characteristics that make them as appealing to food scientists as they can be a nuisance to Britain’s pond owners.

Thriving in still or slow-moving freshwater, the duckweed (or, to use the Latin name, Lemnaceae) family resembles cress when it carpets the surface in a mass of green, and is often mistaken for algae.

And it really does thrive. Duckweed is one of the fastest growing plants in the world, making it a subject of fascination for scientists whether they share Dr Ifie’s research interests or not.

An ideal candidate

“My career to date has focused on understanding how we can process some of the chemicals that plants produce to protect themselves in ways that best help us contribute to more sustainable diets and better health,” Idolo said.


There are lots of alternative proteins out there and people have been getting more interested in things like soy, lentils and beans, yet there are also lots of other plants that can offer great nutrition but haven’t been researched anywhere near as much yet.
Dr Idolo Ifie

In fact, duckweed can contain as much as 40 per cent protein if grown under optimal conditions, meaning it could feasibly serve as an invaluable source if we can only work out how best to take advantage of it.

What’s more, duckweed’s versatility makes it especially attractive.

“It’s rich in protein, contains mineral nutrients and fatty acids, and can grow in a wide variety of environments,” Idolo said.

“Because duckweed is aquatic, it doesn’t require large areas of land like other crops, nor fertiliser. All that means it’s very sustainable and resilient to climate change.”

Duck swimming in duckweed

Enjoyed by ducks – and humans?

The plant’s name itself refers to the fact that waterfowl love it; so too do the frog and toad tadpoles that use its leaves for shelter.

But as the world’s population continues to climb, we face a huge challenge to produce enough food to feed every hungry mouth.

In fact, the UN’s Food and Agriculture Organization suggests that to sate the appetites of 9.3 billion people by 2050, we will need to produce 60 per cent more of it.

So could getting humans to love duckweed too provide a practical solution to this critical problem?

Spread of traditional Northern Thai food

Passing the taste test

Of course, if it was that straightforward and simple, you might already be planning your next duckweed dinner.

Some significant progress has been made in the field, with at least one company in the United States growing lemna ponds to extract the protein rubisco for food production, and the European Food Safety Authority recently confirming two species of duckweed as ‘novel food’.

But while people in some southeast Asian countries have long harvested and cooked the wild, mostly mild-tasting plants, understanding how to cultivate duckweed at scale, process it as an environmentally sustainable source of alternative protein and then incorporate it into tasty dishes enjoyed by an unfamiliar public is more of a challenge.

Intercontinental investigations

“My journey began in Nigeria, at Delta State University,” Dr Ifie recalled.

“I was having an informal conversation about alternative proteins with a colleague in a computer room, chatting about malnutrition and what could be done about it.

“And he just happened to say ‘oh, there’s this plant, duckweed… have you heard of it?’ – so I typed it in, saw how high it is in protein and immediately knew it was something I wanted to research.”

A panoramic view of Idanre hills on a cloudy day

After 17 years of teaching, research and academic roles at multiple African universities, in 2022 Idolo brought his newfound fascination with him to complete a PhD in the School of Food Science at Leeds.

Here, he was the lead author of a study exploring how processing duckweed collected from the Nigerian town of Oghara in a variety of ways would affect the plant’s nutritional qualities.

Dr Idolo Ifie in a lab at The University of Leeds

The goal? To create duckweed powder that can best fortify food or be ingested as protein in the most nutritious way possible, while eliminating any health risks from contaminated water sources.

Dried duckweed powder

If we can supplement high-starch diets with inexpensive protein from duckweed, we can address deficiencies that contribute to malnutrition.
Dr Idolo Ifie

“But to process it into a powder, you need to dry the duckweed through either sun drying, shade drying or sun drying with blanching – and there was very little research into the effects of all these methods on nutrient loss and contamination.”

Idolo took samples from a pond emanating from River Ethiope, which has been linked to heavy metal contamination from nearby oil exploration, and compared them after being dried with each approach and to a freshly collected sample.

“What we found was quite encouraging,” he said. “The duckweed was generally safe, and the blanched-sun-dried samples had increased concentrations of nutrients and bioactive compounds.”

Efficient and effective production, though, is just one hurdle.

“If we want people to eat foods that have been fortified with duckweed for all those extra nutrients, we have to get them to like the flavour and texture,” Idolo said. “We did a brief survey using some cookies, and although people said they would be more willing to try the duckweed-fortified version if they knew it was a healthier option, a lot of people still preferred the taste of the product without it.”

Going global – and beyond?

If the potential for duckweed remains untapped, so too do the research opportunities around it.

Could food manufacturers, investors and authorities seize on the enormous benefits offered by this special weed to improve public health, sustainability and supply efficiencies in one fell swoop?

“That’s why I’m currently applying for further funding,” Dr Ifie said.

“There are so many growing and processing conditions, like light levels and temperatures, that remain understudied – all of which may have different impacts on the plant and how nutritious it can be.

If we work out how to hygienically cultivate duckweed as cheaply and quickly as possible, the outputs could be enormous and go a huge way to helping us feed the world.
Dr Idolo Ifie

Houston, we have a protein?

It’s even been claimed that the plant could go further still; scientists in Australia calculated that sending a four-person crew on a three-year trip to Mars would require 10 tonnes of food, a logistical headache that would be eased if astronauts were able to grow an alternative protein like duckweed within the confines of a space shuttle.

The planet Mars in a dark sky

For now, though, Idolo is focusing on a separate study on the most effective ways to extract the protein from duckweed.

But with research in this area still in its infancy, it would seem the sky – or perhaps even the solar system – is the limit.

Experts

Dr Idolo Ifie

Idolo is Lecturer in Food Processing at the University of Leeds, specialising in phytochemicals, polyphenols and bioactive compounds.

He obtained both his BSc and MSc in Food Technology at the University of Ibadan in Nigeria before completing a PhD in Food Science and Nutrition at Leeds.

Idolo is also a member of the Institute of Food Science and Technology.