Effects of combination of heat treatments and modified atmospheres on strawberry fruit quality

Strawberries (Fragaria ananassa cv Selva) were put in bags with different permeability to CO2, O-2 and H2O vapor, heat treated in an air oven (45degreesC, 3 h) and stored at 0degreesC for 0, 7 or 14 days. After the treatment, the fruit was maintained at 20degreesC for 48 h. The effect of heat treatment and films on fruit firmness, superficial color, anthocyanin content, and decay was analyzed. Heat-treated fruit maintained firmness and was less susceptible to fungal attack than the control. Superficial color development and anthocyanin accumulation were delayed in the case of heat-treated fruit. When the fruits were treated and packed in bags that retain CO2, the effects were enhanced and fruit postharvest life was extended. These results show that the use of heat treatments in combination with refrigerated storage could be a good alternative to keep strawberry fruit quality. Additional improvement can be obtained by performing the heat treatment in bags that allow the CO2 produced as a consequence of the enhanced respiration rate during treatment to be retained.