Circular Ecnomy: Valorization of Mango Peels of Obtaining Nanocellulose (CNF)

The study proposes the use of mango Kent (Mangifera indica) peel residues generated by agroindustrial processes in Northern Peru (3,500 tons/year) for the production of cellulose nanofibers (CNF) as a sustainable valorization alternative. The main objective was to determine the best CNF yield by evaluating two levels of temperature, time, and sulfuric acid concentration. Sample preparation included immersion washing at 90 °C, drying, and sieving, followed by washing with 96% ethanol and steam treatment. An alkaline treatment with 8% NaOH (1:15 ratio) was then applied at 75–80 °C for 4 hours under stirring at 500 rpm, followed by bleaching with an acetate buffer/chlorite solution at 80 °C for 6 hours. Acid hydrolysis with H2SO4 (2%, 6%, and 10%) was performed at a 1:20 ratio for 60 or 90 minutes at 60 °C or 80 °C. The resulting suspension was sonicated (300 W, ice bath, 30 min), washed with distilled water, and dialyzed using 12–14 kDa membranes. Finally, the material was freeze-dried and sonicated at -45 °C to obtain CNF particles. Yields ranged from 86% to 99% based on cellulose content and 18.10% based on dry residue weight, with the optimal condition being 80 °C, 2% H2SO4, and 60 minutes. This chemo-mechanical process represents a low-cost, environmentally friendly alternative for biomaterial production in the region.