Water barrier coating of chitosan/poly (vinyl alcohol)/trans-cinnamaldehyde regulated postharvest quality and reactive oxygen species metabolism of ‘Frutica’ tomato (Solanum lycopersicum L.)

Abstract

The ‘Frutica’ tomato (Solanum lycopersicum L.), a nutritious “king of fruit,” faces restricted marketability in storage. This study focused on enhancing storage longevity and regulating reactive oxygen species (ROS) metabolism in these tomatoes using chitosan (CS), polyvinyl alcohol (PVA), and trans-cinnamaldehyde (CIN) water barrier coatings and investigated their underlying mechanisms. Tomatoes coated with four different coating formulations and uncoated fruit were stored for 30 d at 8 °C and 75% relative humidity. The bioactive films were evaluated for microstructure (scanning electron microscopy; atomic force microscopy), water barrier, and antifungal properties and tested every 5 d for physical and chemical indices, quality, and ROS of the postharvest fruit. The results showed that the addition of CIN increased the structural density, water barrier properties, and Botrytis cinerea resistance of the coatings. The CIN-containing coating significantly improved water loss, firmness, titratable acid (TA) value, color, and appearance; decreased lipid peroxidation; and modulated the ROS scavenging system compared with other treatment groups. Principal component analysis and correlation revealed that the CIN-coated material, characterized by water-barrier properties, contributed positively to the preservation of tomatoes during refrigeration. Water barrier coating facilitates the enzymatic ROS scavenging system in tomatoes, thereby extending their senescence.