New Thinking

Aquatic plant offers protein

The thin, green layer seen on most duckponds might not seem the most attractive culinary option but researchers and food experts believe it holds the promise of being a powerful new source of protein and B12 with some strong provenance value. Amos Palfreyman of FoodHQ spoke to Richard Rennie about duckweed’s potential as a food crop.

IN COMING weeks researchers will be combing same place we are already at with excess nutrients lost and largeEvery 36 hours waterways and lakes around scale water use,” Palfreyman said. you can harvest a crop New Zealand hoping to collect an indigenous variety of innocuous duckweed, the Waitotara’s interest in duckweed, also known as water lentils, came when chief executive and the big technical challenge is how to thin green plant that floats Warwick Tauwhare-George and extract a usable protein on ponds and slow-moving waterways. While prolific around the FoodHQ chief executive Abby Thompson came across it in a Dutch research centre last year. that is functional, can dissolve, has no smell world, the chance to identify a “The Dutch are particularly or taste and can be variety native to New Zealand and good at intense cropping and mixed into other reap the benefits of its dietary properties and local uniqueness have been experimenting with growing duckweed in stacked ingredients. has researchers and food vertical farms indoors in a companies excited. Taranaki Maori corporate highly automated system. At this stage it’s not economic but the Amos Palfreyman Parininihi Ki Waitotara, co-funded duckweed has some very strong FoodHQ by Agmardt and supported by attractions.” FoodHQ, is working to explore Under the right conditions it how the tiny aquatic plant could can double in mass every 24-36 On a per-hectare basis the water prove a valuable, fast-growing hours because of an exponential lentils are six times more efficient protein source. growth pattern. It is protein dense, at protein production than

“There is an understanding that comprising 40-60% of the plant’s soybeans. if NZ is to go down the accepted drymatter, rich in amino acids and “Every 36 hours you can harvest plant protein route that requires vitamin B12, is easily collected a crop and the big technical cropping high-protein plants and much of the water used to challenge is how to extract a like peas we risk ending up in the grow it can be recycled. usable protein that is functional, can dissolve, has no smell or taste and can be mixed into other ingredients.” The only water lentil food product available for consumption in NZ is imported from the United States and is a powder to add to smoothies and drinks, at a cost of about $4 a serve. Southeast Asians eat a variety of duckweed as a vegetable dish known as khai-nam or eggs of the water and compare in taste and texture to combining kale, broccoli and spinach. The iwi project has engaged with Manaaki Whenua’s plant taxonomist Peter Heenan and Maori development general manager Holden Hohaia to SCIENCE: Duckweed samples in the FoodHQ lab. explore the possibility of a native

FISHING: Plant taxonomist Peter Heenan scouring for duckweed samples.

NZ strain of the weed, Lemna disperma.

“Duckweed is not really a plant that gets a lot of attention from taxonomists, with research tending to be around rarer plants. But if we can identify a uniquely NZ variety there is potential here to licence it, not unlike what has been done with manuka honey.”

While it is a simple enough plant to harvest, dry and turn to powder the challenge is to remove remnant flavour and odour without damaging the high vitamin and protein content.

“This will be the biggest challenge and is very much a work in progress.”

Recent Dutch research found a high level of acceptability among consumers for using the plant protein in daily diets despite initial fears they might be put off by associations with pond water.

The powder can be used in a range of applications as a plantbased protein source instead of peas, appealing to the growing vegan-flexitarian consumer market.

An application is due to be lodged to have the plant classed as a novel food suitable for human consumption and it already has approval in the US, Australia and NZ for human consumption.

Waitotara and FoodHQ are working with Massey University’s Professor Benoit Guieysse, founder of NZ’s only spirulina company NZ Algae Innovations, trading as Tahi Spirulina.

“Benoit brings the expertise on the production side of the project, including reviewing best practice for cultivation and setting up an initial pilot pond cultivation system.”

While a bacteria, spirulina shares similarities with duckweed in terms of growing techniques.

With Waitotara being one of Fonterra’s largest milk suppliers with 20,000ha in Taranaki, the iwi group aims to establish a diverse portfolio of agri-food business interests underpinned by a strong sustainability ethos.

“It is still only early days but if we can identify a native version it could be possible for iwi to have their own protected product, sourced off their own land in what’s been an overlooked plant in the emerging plant-based food sector,” Palfreyman said.

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