Exploring an untapped versatile superfood

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.

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.

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.”

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.

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.

“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.

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.

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.