Utilization of cinnamaldehyde and zinc oxide nanoparticles in a carboxymethylcellulose-based composite coating to improve the postharvest quality of cherry tomatoes

Carboxymethylcellulose (CMC)-based film packaging enriched with plant-sourced cinnamaldehyde (CIN) and zinc oxide nanoparticles (ZnONPs) of simple synthesis were prepared in this work. Then, the physico-mechanical and barrier properties and antifungal activities of CMC-based films, including pristine CMC, CIN/CMC, ZnONPs/CMC, ZnONPs/CIN/CMC were investigated. The results indicated that the ZnONPs incorporation produced a nanocomposite film with low transparency, good flexibility and high mechanical resistance. Furthermore, the water barrier capacity and antifungal performance of CMC-based films were significantly improved with the addition of CIN. CMC-based composite film incorporating with both CIN and ZnONPs, in turn, exhibited satisfactory mechanical characterizations, excellent barrier capacities against water and oxygen molecules and anti-Aspergillus niger activity. Moreover, ZnO/CIN/CMC nanocomposite film was significantly effective at inhibiting the weight loss and firmness of cherry tomatoes and in decreasing the total acidity content of these fruits after storage. Our results suggested that the ZnO/CIN/CMC nanocomposite film packaging can improve the cherry tomatoes quality by suppressing physiological the metabolic activities of the fruits during postharvest storage period.