Characterizations of bacterial cellulose nanofibers reinforced edible films based on konjac glucomannan

Abstract

This study was aimed at developing edible films of konjac glucomannan (KGM) with different contents of bacterial cellulose nanofibers (BCNs). The effects of different contents of BCNs (0-4% (w/w)) on the properties of KGM-based edible films were investigated in the present work. The rheological properties showed that the film-forming solutions displayed an entanglement system with G'<G″ at low frequency and gel-like behavior with G'>G″ at high frequencies. SEM indicated that BCNs were well dispersed in the BCNs/KGM films. With the increase of BCNs contents, the surface morphology of the films assessed by AFM displayed an increased trend in the surface roughness. Moreover, the films were formed mainly through hydrogen bonds as indicated by FTIR analysis. XRD, DSC and TGA showed that the crystallinity and the thermal stability of films increased with the increase of BCNs. Meanwhile, barrier properties of films were improved by the addition of BCNs. Additionally, with the increase of BCNs, the tensile strength (TS) of the films increased, while the elongation at break (EAB) was increased and then decreased. Therefore, reinforcement of KGM-based films with BCNs leads to enhance barrier and mechanical properties with promising potential as packaging films for food products.

Keywords: Bacterial cellulose nanofibers; Edible films; Konjac glucomannan.