Chitosan nanoparticles as edible surface coating agent to preserve the fresh-cut bell pepper (Capsicum annuum L. var. grossum (L.) Sendt).

This work synthesized chitosan nanoparticles (CSNPs) by ionic gelation method using sodium tripolyphosphate pentabasic (STPP) and applied as nano-coating agent to extend the shelf life of fresh cut bell pepper (FCP) by preventing the microbial contaminations. The CSNPs were spherical shaped and 22.55 ± 1.69 d.nm sized with ζ-potential of 45.10 ± 1.42 mV confirmed by UHR-SEM, FE-TEM, and ζ-potential size analyses. The crystallinity and functional group changes were determined by XRD and FT-IR analyses respectivelly. The antioxidant activity of CSNPs was determined in terms of DPPH and ABTS scavenging activities. The 1% and 3% of CSNPs were found to be minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) respectively against all tested bacteria. The MBC of CSNPs was exhibited the promising anti-biofilm activity. Therefore, the 3% of CSNPs was used to prepare the chitosan nano-coating (CSNC), and applied on surface of FCP to prevent the microbial contaminations such as fungi, bacteria including Listeria monocytogenes and Salmonella enterica. The experimental results showed that the application of CSNC was maintained the FCP for 12 days at 5 °C without loss of weight, and sensory quality.