Development of cotton fabric impregnated with antioxidant mango polyphenols by means of supercritical fluids

Cotton fabrics loaded with mango polyphenols were developed by means of supercritical solvent impregnation (SSI). Gallic acid (GA) was used as the model substance to determine the influence of pressure (P) and temperature (T) on the process. This method allows high GA loads under 300 bar and at 45 degrees C. These conditions were later implemented to the SSI of mango leaf extract (MLE) and other parameters such as cosolvent %, contact time and depressurizing rate were also studied. High loads of mango polyphenols from different families (GA, iriflophenones, mangiferin and quercetin glycosides) were deposited on cotton fibres using CO2 + 6% ethanol under 300 bar and 45 degrees C, at a fast depressurizing rate of 5 bar/min during 24 h. The antioxidant capacity of the processed samples was also verified by DPPH assay, and the structural changes of the cotton as well as the success of the SSI process by SEM.