Postharvest quality of tomato fruits cv. Andrea treated with ethylene

Tomatoes are one of the most important vegetable crops grown in Brazil and treatments that facilitate ripening control are extremely desirable. The present work was carried out aiming to evaluate postharvest quality of roma-type tomatoes treated with ethylene. 'Andrea' tomatoes were harvested in commercial fields at the mature-green stage, were graded for size and color, and treated with ethylene (100 mu L L-1) for 48 hours at 20 degrees +/- 1 degrees C and relative humidity of 90 +/- 5%. The experiments were carried out using a completely randomized design with four treatments and fifteen replicates (n=10). After ethylene application, tomatoes were stored at two temperatures. One lot remained at 20 degrees +/- 1 degrees C and another one was kept at 12.5 degrees +/- 1 degrees C and relative humidity of 90 5%. Control fruits were kept in the same storage conditions of temperature and relative humidity. For each maturity color change, the following analyses were carried out: color indexes (L *, a* and the b * and its relations), water loss (%), soluble solids (degrees Brix), titratable acidity (g 100g(-1)), and ascorbic acid (mg 100g(-1)). Ethylene application promoted color uniformity in treated fruits. However, there were no significant changes in the other postharvest variables evaluated. Fruits stored at 20 degrees C showed 2.6% of mass loss during storage. Brix/titratable ratio showed slight variation throughout the experiment. Control fruits stored at 20 degrees C changed external color earlier than other treatments in the beginning of the trial, showing no significant difference after that. Postharvest ethylene application was not an efficient technique to hasten ripening of 'Andrea' tomatoes.