Scientists from the University of São Paulo in Brazil are exploring new ingredients, including sunflower seed flour, that can improve the nutritional quality of bread without sacrificing taste or practicality.

One promising option that has emerged is partially defatted sunflower seed flour – a material that is left behind after sunflower oil is produced. This byproduct has has shown the potential for enriching bread with protein, fibre and antioxidant compounds.

According to Science Daily, lead author and biologist Leondardo Mendes de Souza Mesquita said their aim was to optimise the reuse of sunflower seed flour considering its high protein content and chlorogenic acid content.

“Sunflower seed flour has been shown to contain a very high percentage of protein, from 40 per cent to 66 per cent, as well as dietary fibre, iron, calcium, and high levels of chlorogenic acid, a phenolic compound associated with antioxidant, anti-inflammatory, and hypoglycemic effects,” he said, adding the use of sunflower seed flour both increased the nutritional value of bread while lowering the environmental footprint of sunflower oil production.

In order to evaluate how sunflower seed flour performs in baking the research team prepared bread recipes that replaced wheat flour with sunflower seed flour at levels ranging between 10 per cent 60 per cent. Each version was then carefully analysed for its chemical makeup, dough behaviour, and physical characteristics.

The results showed distinct nutritional improvements. The breads that were made using sunflower seed flour contained significantly more protein and fibre than standard wheat bread. At the highest substitution level the bread reached 27.16 per cent protein, compared with 8.27 per cent in conventional bread. The antioxidant levels also rose alongside protein content.

However, despite the nutritional benefits being clear, higher amounts of sunflower seed flour did impact the overall size and texture of the bread loaves. When sunflower seed flour made up 20 per cent or more of the recipe the loaves became smaller and firmer, while changes in crumb structure also led to denser bread with reduced softness.

“However, adding the aqueous extract [SFE] managed to preserve the structure and texture of the breads, keeping them close to those of traditional wheat bread,” Mr Mesquita said.

“This approach allows bakers to gain the nutritional advantages of sunflower seed flour while minimising negative effects in texture.”

The full study was published in ACS Food Science & Technology.