Application of chitosan and gelatin based active packaging films for peeled shrimp preservation: A novel functional wrapping design

- Chitosan and gelatin films enriched with ZEO and PPE improved the shelf life of shrimp.
- Combination of ZEO and PPE led to strong antibacterial activity.
- Influence of the CN on improving shrimp shelf life was insignificant.
- Chitosan and gelatin films could be used as an excellent type of active packaging.

The aim of the present study was to evaluate the effects of chitosan (Ch) and gelatin (Ge) films containing Ziziphora clinopodioides essential oil (ZEO; 0 and 1%), pomegranate peel extract (PPE; 0 and 1%) and cellulose nanoparticle (CN; 0 and 1%), separately and in combination, on survival of Listeria monocytogenes and shelf life extension of fresh shrimp during refrigerated storage. The control and wrapped shrimps were evaluated for chemical (PV and TVB-N), bacterial (mesophilic and psychrotrophic bacteria, Pseudomonas spp., P. fluorescens, Shewanella putrefaciens, lactic acid bacteria and Enterobacteriaceae) and sensory properties (odor, color, texture and acceptability). All wrapped shrimps in Ch and Ge films had lower bacterial counts compared to control (P < 0.05). Final population of L. monocytogenes was decreased 2-3 log CFU/g in treated samples compared to control (P < 0.05). The bacterial population of shrimps wrapped in Ch films were significantly lower than those wrapped in Ge films probability due to the inherent antibacterial property of Ch (P < 0.05). The groups treated with CN had insignificantly lower bacterial count compared straight film (P > 0.05). The Ch group treated with ZEO 1% + PPE 1% + CN 1% had the best antibacterial effectiveness and also the highest organoleptic scores after 11 days (P < 0.05).