Aberystwyth University searchers have developed an innovative approach to improving the aroma of alternative high-protein foods made from fermenting leftover bread crusts with forage grasses, traditionally used to feed livestock.

Smell plays a crucial role in how people perceive taste and the research shows how natural fungal fermentation processes can be used to fine tune the aroma of novel foods produced to help feed the world’s growing population.

By combining surplus bread crusts with protein from perennial ryegrass and fermenting the mixture for up to 72 hours, the team from Aberystwyth University’s Institute of Biological, Environmental and Rural Sciences (IBERS) successfully enhanced both the aroma and nutritional quality of the product.

The study identified and analysed more than 150 different aroma compounds produced through using solid-state fermentation.

Newly published in the peer-reviewed journal npj Science of Food, the findings highlight the potential of developing appealing, sustainable foods which meet the growing demand for alternative proteins while addressing both food waste and food security challenges.

Juan Felipe Sandoval Rueda, the lead author of the study, said: “Smell is essential to our enjoyment of food.

“By understanding how aroma compounds develop during fungal fermentation, we can turn unconventional ingredients into novel food products that are more sustainable and more appealing to consumers.

“After fermentation, the material is dried and made into a protein-rich powder which can be added to other foods such as wheat flour, for example, and used to make protein enriched bread.

“Our study also discovered a new mathematical method of predicting the odour of new food products at an early stage in the process, with potential time and cost savings for industrial food manufacturers.”

Reading University was also involved in the study, which was funded by the UKRI Biotechnology and Biological Sciences Research Council (BBSRC) and industrial partners Samworth Brothers.