Effect of calcium chloride and 1-methylcyclopropene combined treatment on pectin degradation and textural changes of Eureka lemon during postharvest storage

During post-harvest storage, the cell wall properties are closely associated with the physical, chemical, and biological properties of the fruit. The degradation of pectin in the cell walls and middle lamella is critical to these properties. The effects of calcium chloride (CaCl₂) and 1-methylcyclopropene (1-MCP) combined treatment on the pectin degradation, texture, and peel color of Eureka lemon were investigated during post-harvest storage. The in-situ light microscope analysis, rapid method, and FTIR test were used to investigate the spatial distribution, the pectin content, and its degradation. The results showed a reduction in pectin degradation, by 42 d the CaCl₂ and 1-MCP combined treated fruits presented a 36.7% pectin content loss which was lower than the control which was 48.3%. The treated fruits significantly exhibited enhanced textural properties, delayed weight loss, higher total acids, and improvement of other physicochemical properties in comparison to the control. The treatment deaccelerated the fruit peel color change from green to yellow and also had a better visual appearance on the final day. Overall, the results suggest that the control treatment for pectin degradation can reduce the fruit texture decline and peel color change and maintain a good visual appearance. The influence of pectin degradation on the texture and physicochemical properties of lemon provides a theoretical basis for fruit storage optimization, quality control, and shelf-life extension.