Quitosana derivada de quitina de lagosta: atividade antioxidante e antimicrobiana

Introduction: Chitosan has antimicrobial and antioxidant properties, which make it an interesting compound for various applications. Aim: To evaluate the antioxidant and antimicrobial activity of chitosan, derived from lobster chitin (Panulirus aurgus), and chitosan acetate. Methods: The antioxidant capacity of chitosan solutions was determined using the ferric iron reducing capacity (FRAP) and radical scavenging capacity (DPPH) methods. The influence of the concentration (0.5, 1.0 and 2.0% (w/v)) of the polymer and its acetate salt on the antimicrobial activity was evaluated. The minimum inhibitory and microbicidal concentrations were determined through the serial dilution method and the antimicrobial activity by agar diffusion. Attenuated strains of Gram positive and Gram negative microorganisms, fungi and yeasts were used. Results: Chitosan solutions showed moderate antioxidant activity, being higher for chitosan acetate. The antimicrobial activity increased with increasing concentration of the biopolymer and its salt. Both chitosan and its acetate salt had an inhibitory effect on Gram positive and Gram negative microorganisms, as well as fungi. Conclusions: The potential of both raw materials for their use in pharmaceutical and cosmetic products is demonstrated.