Versatile soy protein films and hydrogels by the incorporation of β-chitin from squid pens (Loligo sp.)

Abstract

This study is focused on the preparation and characterization of β-chitin reinforced soy protein films, employing compression moulding as the processing method. β-chitin was extracted from squid pens (Loligo sp.) by a simple alkaline hydrolysis, avoiding the demineralization and decolouration steps used in chitin extraction from other sources, thus reducing the processing time and the production costs of the films. β-chitin was homogenously incorporated into the soy protein matrix, indicating good compatibility between the protein and the polysaccharide. Furthermore, the tensile strength and modulus of the films were significantly improved with the β-chitin addition due to the increase in crystallinity. Regarding the water uptake of the films, equilibrium was achieved in the first four hours of immersion and film integrity was maintained during the entire immersion time, suggesting the interactions among the film forming components; additionally, film solubility decreased with β-chitin concentration. Therefore, a promising multifunctional material was developed in this study.