Impregnación a condiciones supercríticas de antioxidantes naturales provenientes de Ilex guayusa en películas poliméricas

Abstract

Abstract: In this research, polymeric matrices based on chitosan, acetic acid, and distilled water were created. These matrices acted as adsorbents during the CO2-assisted supercritical impregnation technique, in which an ethanolic extract of Ilex guayusa leaves was applied. The antioxidant capacity of the dry extract of guayusa was evaluated. This extract was obtained by ultrasound-assisted maceration, resulting in a total phenol content of 11.60 mg EAG/g of extract, and the antioxidant capacity was determined by the DPPH, FRAP, and ABTS methods, with values ​​of 144.91 ± 0.02, 134.61 ± 0.03, and 116.82 ± 0.02 µmol Trolox/g of dry extract, respectively. Through factor analysis using Fisher's tests, the results corresponding to impregnation performance, total phenol quantification, and antioxidant capacity, color, and mechanical properties of the impregnated and unimpregnated polymer matrices were analyzed to determine their differences. Therefore, it was confirmed that pressure variations between 100 and 200 bar with respect to a temperature of 35°C maximize antioxidant activity in the impregnated biofilms.