Abstract: During postharvest storage, spinach is prone to problems such as oxidation, dehydration, wilting and decay, causing severe losses. In view of this, postharvest spinach was treated with 1 μL/L 1-methylcyclopropene (1-MCP), 0.1% phytic acid (PA) or their combination to explore the effects of preservatives on the physiology and storage quality of spinach. Spinach not treated with preservatives was used as a control. All samples were stored at room temperature (20 ± 1) ℃ and a relative humidity between 80% and 90%. The decay index, mass loss percentage, chlorophyll content, soluble solid content, ethylene release, peroxidase (POD) activity and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity were measured. In addition, sensory evaluation was performed in terms of appearance, morphology and smell. The results showed that all three treatments were effective in maintaining spinach quality. Specifically, compared with the other three groups, combined treatment with 1-MCP and PA significantly enhanced peroxidase (POD) activity and DPPH radical-scavenging capacity, thereby delaying the increase in decay index, mass loss percentage and ethylene release and increasing the chlorophyll content of spinach and maintaining high soluble solid content and sensory evaluation score during storage. As a result, 1 μL/L 1-MCP + 0.1% PA composite treatment had the best preservation effect, which could effectively delay the postharvest senescence and quality deterioration of spinach.

Key words: 1-methylcyclopropene; phytic acid; postharvest physiology; storage and preservation; spinach