Development, modification and characterization of new biodegradable film from basil seed (Ocimum basilicum L.)...

Biodegradable films from basil seed mucilage (BSM) were formed and modified with several di-carboxylic acid crosslinkers; i.e. tartaric acid (TA), malic acid (MA) and succinic acid (SA) with varying acidity and chemical structures, to enhance mechanical properties and water barrier ability. Basil seeds have a reasonable mucilage content and valuable properties; thus, it has the potential to develop valuable new biodegradable films.

We characterized BSM films with the three crosslinkers using Fourier-transform infrared (FTIR) spectra and observed a 1730 cm^-1 CO stretching peak, which confirmed ester linkage between the mucilage and crosslinkers. The crosslinked films showed higher gel fraction than native films. The crosslinked films showed better swelling and water vapor permeability with SA than with TA and MA. Crosslinking led to significant improvement in strain at maximum load. Further, the stress maximum load was comparable to that of commercial low-density polyethylene (LDPE) film. Crosslinked films showed additional homogeneous morphology and an increase in thermal degradation temperatures.

Crosslinking with dicarboxylic acids improved all the key properties of BSM films, including excellent stress and strain at maximum load, improved barrier capability and thermal properties. Thus, these films showed good potential as biodegradable films, especially for food packaging. © 2019 Society of Chemical Industry.