QUALITY AND SHELF LIFE OF THREE STRAWBERRY (Fragaria ananassa) CULTIVARS TREATED WITH HIGH CONCENTRATIONS OF CO2 FOR SHORT PERIOD

Refrigeration and controlled-atmospheres treatments are alternatives to control the growth of Botrytis cinerea during the postharvest and to reduce quality loss in strawberries (Fragaria ananassa). The objective of this experiment was to evaluate the effect of high CO2 concentrations on the development of rots caused by Botrytis cinema, and to determine the shelf life of four strawberry cultivars. The experimental design was split-plot in complete randomized blocks. The evaluation time (3 d and 5 d) was assigned to the main plot; the CO2 concentration (5 % and 10 %) was assigned to the subplot; and the strawberry cultivars were considered as blocks. Means were compared using the Tukey test 0.05). The experimental unit was one fruit and there were five replicates per treatment. In the Mexican cultivars-CP-LE7, Zamorana, Jacona-and the introduced one, Festival, as control, the evaluated variables were: color, firmness, weight loss, rot percentage, total sugars, titratable acidity, total soluble solids, pH, ethanol, and acetaldehyde. Fruits were stored at 3 degrees C under two controlled atmospheres -5 and 10 % of CO2 for 3 or 5 d-, plus 2 d at 20 degrees C +/- 2 degrees C and 50 to 60 % RH. Cultivars CP-LE7, Zamorana, and Jacona were less tasty (SST and AT) than Festival, but CP-LE7 excelled in firmness (22.36 N), and total sugar content (9.02 g 100 g(-1) strawberry); meanwhile, Zamorana lost less weight (0.88 % and 15.23 %) and Jacona produced bright red fruits (L=32.62, degrees h=34.05, C=26.02). No concentration of CO2 and cold modified AT, SST, SST/AT, color, pH, and total sugars at the end of the treatments; however, after 2 d at room temperature, and under normal atmosphere conditions, there are significant changes in quality.