Nixtamalization with Ca(OH)₂ nanoparticles and a solid-lime-particle-free solution: Physicochemical effects on amaranth (Amaranthus hypochondriacus) and corn (Zea mays L.)

The physical properties of amaranth and corn were evaluatedusing Student’s t-test for moisture content, thousand-grainweight, test weight, absolute density, and flotation index.Significant differences (p < 0.05) were observed between thetwo grains. Water absorption profiles at room temperaturewere analyzed by ANCOVA, revealing a higher absorptionrate in amaranth (0.0023 g water/min) than in corn (0.0016g water/min). This study compared amaranth and cornusing two alternative nixtamalization processes: (1) Ca(OH)₂nanoparticles, and (2) a Solid-Lime-Particle-free solution(SLPF). The traditional method was used for comparison.Proximate analysis showed that SLPF-treated amaranth hada higher ash content (3.58 %) than traditionally nixtamalizedamaranth (3.33 %), while the nanoparticle treatment resultedin a higher calcium concentration (6,262 mg/kg) comparedto traditional amaranth nixtamalization (4,163 mg/kg). Thenejayote (steeping liquor) from the traditional nixtamalizationof both grains generated the highest pollution load. TheSLPF method applied to corn reduced the pH to 8.65 andalkalinity to 881.67 mg/L CaCO₃. The use of nanoparticlesduring nixtamalization contributes to increasing calciumcontent, whereas the SLPF method offers an alternative forminimizing effluent pollution during grain processing.