Nutritious corn extrudates enriched with Andean Lupin and pecan nut: Physicochemical, textural, nutraceutical and sensory properties

Abstract

The study aimed to produce nutritious and functional gluten-free corn-based extrudates by incorporating whole Andean lupin flour (WLF) and ground pecan nut (GPN). A D-optimal mixture design assessed the effects of WLF, GPN, moisture levels (13%, 15%, and 17%), and screw rotation speeds (324, 360, and 396 rpm) in a co-rotating twin-screw extruder. The research evaluated compositional properties, total phenols (TPC), condensed tannins (TCT), antioxidant capacity, expansion, hydration, mechanical properties, pasting behavior, and sensory attributes. High-performance liquid chromatography (HPLC) was used to analyze phenolic acids, flavonoids, and catechins. WLF enhanced protein, fiber, and ash content, while GPN increased TPC, TCT, and antioxidant capacity. Moisture was identified as the key factor affecting all variables. Quadratic models explained the bioactive compound behaviors, and linear models described other properties, with R²adjust values between 0.87 and 0.99. Significant correlations were found between protein, ash, fiber, TPC, ABTS, and TCT. The optimized extrudates exhibited a 58% increase in protein, a 32% rise in phenols, and notable improvement in antioxidant capacity. Consumer preference favored extrudates with higher GPN content, while those with higher WLF content were tasteless. Optimal extrudates containing over 3.2 g/100 g GPN showed enhanced profiles of phenolic acids, flavonoids, and catechins.