Preparation and application of edible agar-based composite films modified by cellulose nanocrystals

In this paper, agar/gelatin (AG/GE) composite film modified by cellulose nanocrystals (CNC), agar/gellan gum (AG/GG) and agar/kappa-carrageenan (AG/KC) composite films modified by CNC and calcium chloride were pre-pared and their properties were investigated. The results showed that the three prepared nanocomposite films exhibited dense and smooth surface structure, and their tensile strength (TS), elongation at break (EB) and light transmittance were larger than 60 MPa, 21 %, 80 % at 660 nm, respectively. Their water swelling rate (SR), water solubility (WS) and water vapor permeability (WVP) were lower than 155 %, 33 % and 6.8 x 10(-11)g m/m(2) Pa s, respectively. These three prepared films not only exhibited better comprehensive properties than those of the existing studies, but also possessed edible, good light transmittance and heat seal performance, especially, possessed better fresh keeping performance than plastic-based food packaging film when they were used to preserve strawberry through packaging or coating methods.

Automated summary

This paper investigated the properties of various agar/gelatin composite films modified by cellulose nanocrystals (CNC), as well as agar/gellan gum and agar/kappa-carrageenan composite films modified by CNC and calcium chloride. The results showed that these composite films had dense and smooth surface structures, with high tensile strength, elongation at break, and light transmittance, along with low water swelling rate, water solubility, and water vapor permeability. These films not only exhibited better comprehensive properties than existing studies, but also showed good performance in preserving strawberries.