Effect of ethylene concentration on quality parameters of fresh tomatoes stored using a carbon-heat hybrid ethylene scrubber

Tomato fruit were stored in cold rooms at 8 °C containing an adsorbent–catalyst device including activated carbon–1% Pd either alone or with a heater (175 °C) programmed to heat at 3 h pulse intervals. Cold rooms without the adsorbent–catalyst system were used as controls. The use of the device led to very low concentrations of both ethylene and CO2 inside the cold rooms when compared with activated carbon–1% Pd alone or control rooms. In addition, the parameters related to ripening such as respiration rate, ethylene production, 1-aminocylcopropane-1-carboxylic acid (ACC, free and conjugated), colour changes, softening, decrease in total acidity (mainly citric and ascorbic acids) and lycopene were significantly higher in stored tomato fruit in control rooms than in those stored in cold rooms with both adsorbent–catalyst systems. The magnitude of the delay in these parameters was always significantly greater with the use of the device with respect to activated carbon–1% Pd alone. Thus, this device could be considered as a new tool to eliminate the ethylene surrounding fruit and vegetables in storage areas, avoiding the detrimental effects of ethylene action and leading to maintenance of their postharvest quality. Other additional advantages are the auto-regeneration process, when heat pulses were applied to the adsorbent–catalyst system, and the fact that it is an environmentally friendly technology.