Optimized extraction, characterization, and cytotoxicity assessment of biodegradable Nopalea cochenillifera Salm-Dyck mucilage

Mucilage is a plant-derived polysaccharide-rich complex with valuable physicochemical properties for food, cosmetic, and pharmaceutical applications. This study optimized the extraction of biodegradable mucilage from Nopalea cochenillifera Salm-Dyck and evaluated its physicochemical, thermal, technological, and cytotoxic characteristics. A Box-Behnken design was employed using water ratio (1:2, 1:6, and 1:10), temperature (50, 70, and 90°C), solvent (ethanol, isopropanol, and acetone), and solvent ratio (1:2, 1:6, and 1:10) as independent variables. The extracts were characterized using UV-Vis, Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and differential scanning calorimetry (DSC), as well as molecular size and weight, X-ray diffraction (XRD), and rheology analyses. Cell viability was assessed using RAW 264.7 and HEK 293 cell lines. Optimization increased mucilage yield by 14.6%, with higher levels of soluble carbohydrates and reducing sugars, and reduced protein content. The mucilage remained stable at high temperatures, exhibited an amorphous structure, and was chemically rich in carbohydrates, displaying pseudoplastic behavior. Additionally, high cell viability (>100 µg/mL) was observed for both cell lines. In conclusion, the mucilage from Nopalea cochenillifera Salm-Dyck represents a promising material for applications across various industries as a substitute for non-biodegradable polymers.