Mechanical, melt flow, morphological, thermostructural and antibacterial properties of chitosan/ linear low-density polyethylene blend for selected food (banana) packaging film / Siti Aishah Mohd Isa

The world are facing excessive dumping of plastics wastes especially from packaging food industries. The food industries also need long shelf life as food degradation caused by the growth of microorganism, had reduced the quality of food products. Fresh food product packaging during import and export process especially for fruit product need proper packaging. In this study, an antimicrobial agent and polymer which are in demand for food packaging application had been developed. This research is related to the production of an antibacterial packaging which use chitosan and cinnamaldehyde acting as antibacterial (AM) agent. Different varying compositions 5 to 15wt% of chitosan with fixed 1% cinnamaldehyde were compounded with 85-95wt% of Linear Low- Density Polyethylene (LLDPE) using Twin Screw extruder and Blown film process, to produce two different antibacterial packaging, LLDPE/Chitosan/Cinnamaldehyde and LLDPE/Chitosan. The effects of chitosan incorporation on LLDPE were tested for physical, mechanical, thermal, morphology, antibacterial and rheological behaviour. For first stage blending process, increase percentage of chitosan/LLDPE with cinnamaldehyde had resulted in increased melt flow index (MFI) than Chitosan/LLDPE blend. The MFI value showed two different composites suitable for film blowing process which are in range of 0.34 g/10min to 0.78 g/10min. In general, addition of increase chitosan in LLDPE film blend with and without cinnamaldehyde showed an increase in 21% to 32% of tensile strength and young modulus. 15wt% chitosan/LLDPE with 1% cinnamaldehyde showed highest increase in tensile strength and young modulus, and decrease in elongation at break. From Zone of inhibition test, antibacterial action were found to exhibit Gram-negative bacteria (E.coli) with the presence of chitosan in the film blend. The highest zone of inhibition was found for 5% chitosan/LLDPE film without cinnamaldehyde having zone inhibition at 11.25mm compared to 15% chitosan.