Properties of chitosan–papain biopolymers reinforced with cellulose nanofibers

Abstract

There is currently a strong tendency toward the use of biodegradable packaging produced from biopolymers containing active substances. Papain can be used in active packaging. The aim of this paper was to study the effect of cellulose nanofibers (CNF) and papain on the structural, mechanical, and thermal properties of films of chitosan. The experiment was performed with CNF and papain concentrations ranging from 0%–8% and 0%–10%, respectively. The CNF increased the water solubility of films. Lower water vapor permeability values were observed for the films with 4% CNF and papain concentrations up to 6%. Films reinforced with CNF and without papain were rigid and more resistant. Films incorporated with papain and with or without CNF reduced the tensile strength, the percentage of elongation, and the resistance to perforation. The addition of papain improved thermal stability. The films with 2% papain and 4% CNF presented the best results for the parameters studied.

Practical applications There is a tendency toward the use of biodegradable packaging produced from biopolymers containing active substances. Papain can be used in active packaging. The aim of this studied was to analyze the properties of chitosan films with cellulose nanofibers (CNF) and papain. The incorporation of papain reduced the mechanical properties of the films with and without CNF and improved thermal stability. The addition of papain allowed to obtain films with good properties that allow them to be applied as active films.