Postharvest UV-C treatment combined with 1-methylcyclopropene (1-MCP), followed by storage in continuous low-level ethylene atmosphere, improves the quality of tomatoes

Mature green tomatoes (Solanum lycopersicum L. cv Neang Pich) were exposed to 13.6 kJ m^-2 UV-C or 0.5 µL L^-1 1-MCP or combination of 13.6 kJ m^-2 UV-C and 0.5 µL L^-1 1-MCP, with appropriate untreated controls. After treatment, tomatoes were stored in air containing 0.1 µL L^-1 ethylene at 20°C and 100% RH. The untreated fruit ripened significantly faster than those of all other treatments. UV-C treatment alone was able to delay fruit ripening by up to 5 days longer compared to untreated fruits whilst the additional of 1-MCP further delayed fruit ripening. UV-C and 1-MCP treatments alone or in combination had significantly slower ethylene production rates throughout the storage period. The fruit treated with the combination of 1-MCP and UV-C was significantly firmer and had higher total phenolic content compared to that of the other treatments. However, there was no difference between treatments in soluble solids content/titratable acids ratio, chlorophyll content, lycopene content and total antioxidant activity. These results show that UV-C and 1-MCP treatment delay ripening and improve the quality of tomatoes in the presence of low-level ethylene during storage. This new treatment could be used to extend the shelf-life of mature green tomatoes through the supply chain without the use of refrigeration.