Development and characterization of gelatin/carboxymethyl cellulose based polymeric film with inclusion of ionic liquid to enhance the shelf life of food

Abstract

Gelatin is the key biopolymer with the potential uses in numerous sectors since it is biodegradable and biocompatible. But for instance, food packaging material gelatin itself is not so stable and flexible. In order to overcome this drawback, we have constructed a carboxy methyl cellulose (CMC) and gelatin-based polymeric films at a temperature of 55 °C. A polymeric film with the addition of ionic liquid (IL), shows tremendous antibacterial and antioxidant properties towards food packaging. Ionogel films show different properties with different compositions of ionic liquid (IL0%, IL5%, and IL20%). The characterization of prepared polymeric films has been carried out for their surface morphology, thermal stability, UV shielding, optical properties, smoothness, and antimicrobial properties. The antibacterial activity of polymeric film (PF@IL20%) was tested on both Gram-negative E. coli (Escherichia coli) and Gram-positive S. aureus (Staphylococcus aureus) bacteria. In particular, PF@IL20% exhibits potent activity against E. coli and S. aureus with MIC values of 7 ± 2 μg mL−1 and 13 ± 2 μg mL−1 respectively. It was observed that ionogel matrix shows excellent antibacterial and antioxidant properties toward food packaging and their antibacterial mechanism was explored by SEM and AFM analysis. Further, ionogel PF@IL20% was applied for food (red apple) packaging abilities and with inclusion of 20% ionic liquid exhibited exceptional food wrapping applicability, which increases the shelf life of red apples by preventing air-oxidation.