With rising demand for more nutritious substitutes for conventional wheat products, researchers are investigating innovative components that elevate dietary value without compromising usability. A particularly viable candidate is partially defatted sunflower seed flour (SF), derived as a residue from sunflower oil extraction processes. This often-overlooked byproduct demonstrates remarkable capabilities for fortifying bread with elevated levels of protein, dietary fiber, and potent antioxidant substances.
“Our objective was to maximize the utilization of sunflower seed flour, taking into account its substantial protein levels and rich chlorogenic acid composition,” states biologist Leonardo Mendes de Souza Mesquita, presently affiliated with the Institute of Biosciences at the University of São Paulo (IB-USP) in Brazil. As the principal author of a research paper featured in ACS Food Science & Technology, he highlights the strategic repurposing of this material.
Evaluating Sunflower Flour’s Role in Bread Formulations
In order to assess the integration of sunflower seed flour into baking applications, the scientific team developed various bread formulations substituting wheat flour (WF) with SF at substitution rates from 10% up to 60%. Comprehensive evaluations were conducted on the chemical composition, dough rheology, and physicochemical properties of the resulting loaves.
“Analyses reveal that sunflower seed flour boasts an exceptionally high protein concentration, ranging between 40% and 66%, along with abundant dietary fiber, iron, calcium, and elevated quantities of chlorogenic acid—a bioactive phenolic known for its antioxidant properties, anti-inflammatory actions, and potential to lower blood sugar levels,” Mesquita elaborates. He further emphasizes that incorporating this byproduct not only enhances the overall nutritional profile of bread but also mitigates the ecological impact associated with sunflower oil manufacturing. Moreover, since it is available at minimal cost to prevent landfill disposal, sunflower seed flour represents an economical addition for food producers.
Significant Enhancements in Protein Content and Antioxidant Capacity
The experimental outcomes revealed substantial nutritional upgrades. Loaves incorporating sunflower seed flour exhibited markedly higher protein and fiber contents compared to those made solely from wheat flour. Notably, at the maximum substitution rate, protein levels soared to 27.16%, a stark contrast to the 8.27% found in standard wheat bread. Antioxidant capacities increased proportionally with protein enrichment.
Antioxidant efficacy was quantified using Trolox equivalents, a water-soluble vitamin E derivative employed as a benchmark. The antioxidant values in breads enriched with sunflower flour far surpassed those in pure wheat flour versions, underscoring superior free radical scavenging abilities.
“These findings affirm the health-promoting attributes of sunflower seed flour, particularly in mitigating oxidative stress,” Mesquita affirms. He additionally points out robust inhibitory effects on key digestive enzymes, such as α-amylase (92.81% inhibition) and pancreatic lipase (25.6% inhibition), indicating that SF-enriched bread could decelerate the breakdown of carbohydrates and lipids, potentially aiding metabolic health.
Safe Processing Methods and Contaminant-Free Residue
A critical aspect of the study pertains to the production methodology for sunflower oil. The investigators note that industrial operations predominantly employ mechanical pressing techniques, eschewing chemical solvents. Consequently, the residual flour remains untainted by extraction-related contaminants, save for any naturally occurring residues from sunflower farming practices.
Although the nutritional advantages were unequivocal, elevated SF inclusions influenced sensory and structural attributes. Substitutions at 20% or higher resulted in reduced loaf volumes and increased firmness. Alterations in the crumb matrix further contributed to a denser texture and diminished crumb softness.
“Nevertheless, the incorporation of an aqueous extract (SFE) effectively maintained the structural integrity and textural qualities of the breads, rendering them akin to conventional wheat loaves,” Mesquita observes. This method enables bakers to harness the full nutritional prowess of sunflower flour while curtailing adverse impacts on mouthfeel and appearance.
Optimizing Bread with Sunflower Aqueous Extracts
The SFE is obtained through a straightforward process: sunflower seed flour is combined with water, agitated, and then filtered, requiring no further mechanical or chemical interventions. Mesquita proposes that subsequent investigations could examine scenarios where SFE entirely supplants SF or is combined in varied proportions. This would empower commercial bakeries to refine formulations optimized for large-scale production and consumer preferences.
Advancing Sustainability via Circular Economy Principles
This investigation aligns with broader initiatives to repurpose agro-industrial residues productively. “Converting byproducts into valuable commodities is a cornerstone strategy for fostering a circular economy and minimizing resource depletion,” Mesquita asserts. He underscores how partially defatted sunflower seed flour not only bolsters human nutrition but also yields environmental conservation and economic efficiencies, fulfilling the triple bottom line of sustainability—people, planet, and profit.
The circular economy paradigm fundamentally challenges the linear model of extraction, production, and disposal. It promotes prolonged material circulation, value optimization, and resource renewal across lifecycle stages. Here, a previously undervalued byproduct evolves into a bioactive bread enhancer, simultaneously improving product quality and curbing waste generation.
Collaborative Research Efforts and Support
The project drew expertise from researchers at the Multidisciplinary Laboratory of Food and Health (LabMAS) within the School of Applied Sciences at the State University of Campinas (FCA-UNICAMP) in Limeira, as well as the Laboratory of Food Technology and Nutrition at the Federal University of São Paulo (UNIFESP) on its Baixada Santista campus. Financial backing was secured from FAPESP via six distinct grants (13/04304-4, 20/15774-5, 18/14582-5, 20/08421-9, 15/00658-1, and 19/13496-0). Subsequently, Mesquita was awarded a Young Researcher Grant for his initiative titled “Sustainable Innovations: The Biorefinery Revolution through the Valorization of Macroalgae Using Renewable Solvents Toward a (Green/Blue) Economy.”
