A group of scientists from Hong Kong have demonstrated that waste bread can be used to generate biopolymer feedstock succinic acid. The new process not only uses food waste as a renewable feedstock, it also addresses the dependence on petroleum as the main source of both chemicals and energy.

Using waste bread from Hong Kong University’s coffee shop, the research team – comprised of Cho Chark Jeo Leung, Anaxagoras Siu Yeung Cheung, Andrew Yan-Zhu Zhang, Koon Fung Lam and Carol Sze Ki Lin – fermented the bread chunks using different micro-organisms. Their study found that this bio-based route to succinic acid not only consumes less energy than other processes, it also yields the highest conversion rates of the bioplastic feedstock, at 0.55 g of succinic acid per each gramme of bread. That is higher than the conversion rate of alternative feedstocks, including wheat, corn or rapeseed.

The researchers said their process could potentially be utilised to transform no-value food waste into succinic acid, adding that bread waste could potentially serve as a feedstock for a range of other products.