Safflower cake as an ingredient for a composite flour development towards a circular economy: extrusion versus conventional mixing

[Display omitted] •Composite flour elaboration increases nutritional composition.•Extrusion process increased antioxidant activity.•Extruded composite flours presented lower moisture and lipids content.•The use of extrusion reduced the presence of mycotoxins.•Oil and water absorption were reduced using extrusion. Food waste is responsible for the loss of 1.3 billion tons of food, some of which are related to by-products with great nutritional and energy potential that are still underexplored, such as safflower cake derived from the oil extraction industry. Therefore, the aim of this study was to evaluate the effects of incorporating safflower cake (Carthamus tinctorius) and the mixing method used to produce composite wheat-based flour in order to develop a new ingredient. The results were analyzed using ANOVA, and the Tukey test was applied at a significance level of 5 %. The composite flours obtained by the conventional mixing method showed, when compared to wheat flour, a higher concentration of proteins (+5g 100 g−1), minerals (+86 mg kg−1 of Fe, +30 mg kg−1 of Zn), phenolic compounds (15 mg GAE g−1), flavonoids (0.3 mg QE g−1), and lower oil absorption (−0.5 g oil g sample-1), making them suitable for hot flour-based sauces, salad dressings, frozen desserts, cookies and fried products. While extruded composite flours presented better homogenization, reduction of moisture (1 g 100 g−1), lipids (3 g 100 g−1), and mycotoxin concentrations, increased antioxidant activity (DPPH −0.07 IC50 mg/L and ORAC +9 µmol Trolox Eq/g), water absorption and solubility indexes, and oil absorption index, making it suitable for bakery products, meat, and dairy sausages. The developed composite flour proved to be a good nutritional ingredient; thus, its consumption can represent an important nutritional strategy with low production costs, as well as a sustainable solution, reducing food waste and, therefore, toward the concepts of the circular economy.