Scientists upcycle sunflower oil waste for high-protein, nutrient-rich bread
The team’s experiments showed that substituting a portion of wheat flour with the sunflower byproduct produced bread with markedly improved nutritional profiles while maintaining acceptable texture and sensory qualities for consumers.
BRAZIL – Researchers at the University of São Paulo have pioneered a breakthrough in sustainable baking by transforming partially defatted sunflower seed flour, a low-cost byproduct of industrial sunflower oil extraction, into a functional ingredient that significantly boosts the protein, fiber, and antioxidant content of bread.
Published in early February 2026, the study demonstrates how replacing from 10% to 60% of wheat flour (WF) with this sunflower flour (SF) creates loaves with double the protein levels of traditional bread, enhanced dietary fiber for better digestion, and elevated antioxidants like chlorogenic acid, which combat oxidative stress and support metabolic health.
The innovation addresses two pressing challenges: the global pursuit of healthier wheat alternatives amid rising demand for functional foods, and the circular-economy need to repurpose 30 to 40% of sunflower seeds discarded as waste post-oil pressing, which costs producers millions annually in disposal and enriches landfills.
In laboratory trials, the reformulated bread delivered significantly more protein and dietary fibre per slice and contained higher levels of antioxidant compounds compared with control loaves made from 100% wheat flour.
Beyond nutrition, the research highlights circular‑economy benefits: the partially defatted sunflower seed flour is derived from the residue left after industrial oil extraction, a material that is often underused or discarded.
By converting this waste stream into a value‑added ingredient, the approach could reduce processing losses at oil mills and provide a low‑cost, locally sourced alternative to imported or commodity wheat in some markets.
Sunflower seed flour has been shown to contain a very high protein content of 40% to 66%, as well as dietary fibre, iron, calcium, and high levels of chlorogenic acid.
“Our aim was to optimize the reuse of sunflower seed flour considering its high protein and chlorogenic acid content,” says lead author and biologist Leonardo Mendes de Souza Mesquita, at the Institute of Biosciences of the University of São Paulo (IB-USP) in Brazil.
The researchers emphasized that using such by‑products can lower the environmental footprint of food production while creating new revenue streams for processors.
The findings, published in ACS Food Science & Technology, revealed that breads formulated with sunflower seed flour contained significantly more protein and fiber than standard wheat bread.
Bread with the highest substitution of sunflower seed flour reached 27.16% protein, compared with 8.27% in conventional bread. Antioxidant levels also increased alongside protein content.
“The result reinforces the potential of sunflower seed flour to promote health benefits associated with reducing oxidative stress,” says Mesquita.
He also notes strong inhibition of digestive enzymes, including α-amylase (92.81%) and pancreatic lipase (25.6%).
This opens up opportunities to develop bread containing sunflower seed flour or its aqueous extract (made by mixing sunflower seed flour with water and filtering the mixture), which can slow the digestion of starches and fats for health benefits.
The research aims to explore productive uses for industrial leftovers, which, when reused, can reduce costs by 4% and environmental impact by 11-19%.
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