The Prince of Wales said advances made by an eco-packaging firm since it won £1 million from his Earthshot Prize are “breathtaking”.
William toured the factory of Notpla, which was awarded the funds after impressing judges with its biodegradable cartons made from seaweed, on Tuesday.
The Earthshot Prize was established by William to find solutions to “repair” the planet.
Notpla – short for not plastic – scooped its Build A Waste-Free World award last year.
Shown a new development – injection-moulded seaweed and plant extracts that can be used for cutlery – he said: “It’s breathtaking to see the advances you’re making already.
“That’s really exciting.”
When research engineer Callum Wardle told the future king he could eat the material, William joked: “It might take me a while.”
Before developing cartons, Notpla co-founders Rodrigo Garcia Gonzalez and Pierre Paslier created an edible bubble filled with water.
William donned a blue lab coat to make biodegradable film that can be used to cover food and, impressed by the research scientists’ work, joked: “Where there’s a Bunsen burner, there’s trouble.”
At the end of his visit, William went to a nearby pub, where he ate pizza served on a tray made from seaweed.
Notpla has launched a range of coated boxes with Bidfood UK, a foodservice distributor with more than 45,000 customers across the UK.
When William met existing and potential customers of the biodegradable packaging firm, he asked how to give businesses the “confidence” to try a new product like Notpla.
Darren Ungless, director of buying at Bidfood, said said they needed to “convince” some of the big decision-makers to come on board to make a difference.
After the visit Notpla co-founder Pierre Paslier said the Earthshot Prize had given his business a huge boost of credibility among potential clients but there were issues with companies still being dependent on plastics.
He said: “Today we’re seeing that companies that invest in sustainability, they grow twice as fast as companies that don’t.
“So if you want to stay in business, you’ve got to switch your mindset.”