Flour power: a new rise for wasted bread

Bread is one of the most wasted foods in the world, with approximately ten percent of all manufactured bread wasted worldwide.

Globally, that’s around 900,000 tonnes each year. In New Zealand alone, it’s roughly 24,000 tonnes, with much of it destined for landfill.

Now, students at Waipapa Taumata Rau, University of Auckland are turning that waste into a real-world sustainability project, analysing the environmental footprint of flour made from unsold supermarket loaves.

In a course led by Dr Febelyn Reguyal, senior lecturer in Civil and Environmental Engineering, students compared the life cycle impact of upcycled bread flour with imported wheat flour from Australia, analysing factors such as energy use, emissions and water consumption.

Reguyal partnered for the project with Rescued Kitchen, an Auckland company that repurposes surplus food into new products.

Six groups presented their life cycle assessment (LCA) reports to the clients, Diane Stanbra and Royce Bold, co-founders of Rescued Kitchen. They reported that Rescued flour offers major environmental benefits compared to regular flour, using far less water, land and fossil fuels, and producing much lower carbon emissions.

Reguyal, an expert in sustainability, resource efficiency and LCA, says the project was designed to give students hands-on experience in applying sustainability tools to industry challenges.

"These findings will guide the Rescued team by identifying which stages and processes can further improve environmental performance," she says.

Rescued Kitchen is the country’s market leader in upcycled food. Their bread flour also has a long shelf life of two years, freeze-thaw stability, and complete substitution potential.

Stanbra first had the idea for it all in 2018 while living in Australia.

"I saw products being made from surplus fruits and vegetables, and thought, why can’t we do the same in New Zealand?"

When her co-founder Royce Bold later highlighted the scale of the country’s bread waste problem, the pair began experimenting.

"Armed with a NutriBullet and home oven, Royce created the first batch of Rescued Bread Flour in September 2021," she says.

"Since then, we’ve spent the last four years in research and development building a scalable, sustainable, and transferable solution that will prevent commercial bread waste for New Zealand and the world."

Stanbra says learning about the circular economy was a “game-changer” in shaping how the business operates. Beyond its ingredients, Rescued Kitchen’s circular-economy principles extend to recycled packaging and re-use of by-products.

"To June 2025, we have processed and returned over 170 tonnes of surplus bread, fruit and vegetables to manufacturing, saving over 75,000kg of CO₂ emissions," she says.

"All going to plan, the students will be able to see the results of their work in action in 2026 and beyond."

Reguyal says the collaboration has shown students how research and innovation can directly address one of the most pressing food-waste issues of our time.

"It’s exciting for students to see how sustainability concepts can translate into real-world impact," she says.

She adds that the students’ findings will offer valuable evidence to help companies like Rescued Kitchen keep improving environmental performance - and that she plans to continue the industry-partnership model with a different company each year.