Andean lupin and pecan cakes as sustainable ingredients for breakfast cereals: A by-product approach to functional food development

• Defatted Andean lupin and pecan nuts, as protein-rich by-products, improved gluten-free corn extrudates by increasing protein (16–23.5%) and fiber (16–89%) content. • Enhanced antioxidant properties were observed with significant gains in phenolic compounds, tannins, and radical-scavenging capacity. • Defatted pecan nut contributed chemoprotective effects, enriching flavonoids and catechins, including rutin and epigallocatechin gallate. • Technological feasibility was confirmed for blends with ≤20% by-products, maintaining good expansion and extrusion properties. • Sensory acceptance was linked to crispiness, while prolonged dryness and bitterness negatively impacted consumer preference. This study aimed to enhance corn extrudates with defatted Andean lupine (DLP) and pecan nut (DPP) to improve their nutritional and functional properties. Eleven formulations were developed using a D-optimal mixture design and processed under controlled twin-screw extrusion conditions, varying corn grits (CG) from 60 to 100%, and partially replacing it with DLP and DPP at levels ranging from 0 to 20%. The composition, bioactive compounds (phenolics, tannins, antioxidant capacity), and physical properties were analyzed, along with HPLC quantification of phenolic acids, flavonoids, and catechins. Sensory evaluation was performed using the Temporal Dominance of Sensations (TDS) method with a balanced incomplete block design, followed by a 9-point hedonic scale to assess overall acceptability. The inclusion of high levels of defatted by-products from Andean lupin and pecan, which increased the protein, lipid and fiber contents, exerted a negative synergistic effect on the extrusion process, reducing extrudate expansion. However, the results indicated that formulations containing up to 20% DLP and DPP, or individually up to 14% DLP and 20% DPP, maintained excellent expansion (>3.5) with reduced water absorption and solubility, suggesting lower starch digestibility. DPP significantly enhanced phenolic and tannin content, while DLP contributed protein, fiber, and lipids. Sensory analysis revealed that moderate DLP and DPP levels improved texture and crispiness, whereas excessive DLP led to bitterness. Balanced formulations, particularly those rich in DPP, showed higher acceptability. The enriched extrudates exhibited an improved phenolic profile, positioning them as a nutritious and functional processed food.