The Use of Nixtamalization Waste Waters Clarified by Ultrafiltration for Production of a Fraction Rich in Phenolic Compounds

Clarified nixtamalization waste waters rich in calcium and polyphenols were subjected to ultrafiltration. The effluent was analyzed for its concentration of soluble solids, total solids content, pH, conductivity, turbidity, density, polyphenols, carbohydrates, total organic carbon, calcium content, and antioxidant activity. The operating conditions were as follows: transmembrane pressure 172 kPa, feed flow rate 58 L h⁻¹, and temperature 25 °C. We analyzed the separation process for water permeability, fouling index, process resistance parameters, and flux recovery. A clear fraction rich in polyphenols (951.85 ± 6.99 mg L⁻¹) with antioxidant activity (1.56 ± 0.00 µM Trolox mL⁻¹) was produced from extract, while calcium compounds (3155.3 ± 5.24 mg L⁻¹) were concentrated in retentate. Finally, we determined the mass retention of the membrane for soluble solids (100 %), carbohydrates (80.05 %), polyphenols (20.25 %), total organic carbon (61.08 %), and calcium (82.91 %). We conclude that this membrane process is a realistic approach to recovery of bioactive components.