TOMATO FRUIT QUALITY RETENTION DURING STORAGE BY 1-MCP TREATMENT AS AFFECTED BY CULTIVAR AND RIPENING STAGE AT HARVEST

Abstract

Four tomato cultivars ('Daniela', 'Patrona', 'Cherry' and 'Raf') at two ripening stages (pink and red, for the 3 first cultivars, and breaker and light pink for 'Raf') were treated with two 1-MCP doses (0.3 and 0.5 μL L -1 ). Fruit were stored at 10°C and 90% RH for 4 weeks. Samples were taken weekly, half to study fruit quality parameters during cold storage and half left at 20°C for 1 week (shelf- life). Weight loss, colour, ethylene production, °Brix/titratable acidity ratio, firmness and decay were analysed. For all cultivars and ripening stages, the treatments were effective in reducing weight loss and rate of softening, and retarding colour changes and °Brix/titratable acidity ratio changes, either during cold storage or shelf-life. A positive relationship could be established between 1-MCP dose and the different analysed parameters, the 0.5 μL L -1 dose being the most effective during cold storage and further shelf-life. For most cultivars and ripening stages, no reduction of ethylene production was detected, as a consequence of 1-MCP treatments. This might be because in tomato fruit, the ethylene climacteric peak occurred at the breaker stage, and thus at harvest all cultivars were climacteric, and only decreases in ethylene production were observed during cold storage and shelf-life. However, blocking of the ethylene receptors by 1-MCP treatment inhibited changes in fruit quality properties which are likely to be ethylene-dependent. Also, a reduction in decay was observed for those tomato fruit treated with 1-MCP, especially with the 0.5 μL L -1 1-MCP dose and harvested at the late ripening stage; almost no decay was observed during cold storage and between 2-4 fold lower recorded during shelf-life.