Expanded corn extrudates with Andean amaranth and canihua. Part I: expansion, color, textural properties, pore structure, and consumer acceptance

Andean grains, specifically amaranth and canihua, possess unique nutritional profiles that make them highly valuable for novel food development via processing methods like extrusion. This study investigated the physical, textural, and sensory properties, as well as-pore structures of corn-based extrudates substituted with amaranth or canihua (20, 30, 40, and 50% Degree of Substitution (DS) across three Target Moisture Content (TMC: 14, 16, and 18%). Extrudates containing amaranth gave similar expansion index (8.89–12.72), comparable to the corn reference (10.43–12.90), as well as hardness and crispness. Conversely, the addition of canihua severely inhibited expansion and reduced crispness, a finding correlated with its high lipid and fiber content, which created a denser and thicker air cell-wall structure. Color changes ( L*, a*, b* , and ∆E) indicated that Maillard reactions were more pronounced in high-protein amaranth samples at low TMC. Consumer perception test showed that amaranth extrudates (up to 50% DS) maintained high acceptability, similar to the corn reference. In contrast, canihua extrudates had a significant lower acceptance, primarily influenced by the DS level. These results confirm the high viability of amaranth for producing expanded snacks with competitive sensory characteristics, thus motivating a subsequent investigation (Part II) focusing in the molecular properties and structural implications of the selected amaranth-containing formulations.