Abstract
The effects of calcium-chelate treatments on extending the postharvest life of carambola (Averrohoa carambola L.) fruit were examined. After harvest, fruit were dipped in 0, 250 and 500 ppm Ca-EDTA solution for 20 min with immersion of its peduncle during 7 days of storage at 30°C. The effects of calcium treatment on postharvest life, the concentration of calcium and the form of oxalate crystals were analyzed. 1) Fruit treated with 250 ppm Ca-EDTA solution were visibly acceptable for marketing after 7 days of storage. The fruit firmness and concentration of oxalic acid in these fruits were higher than those undergoing other treatments, whereas the respiration rate was lower in the oxalic acid-treated fruit. 2) In all portion of the fruit, the Ca concentration increased after treatment. The Ca concentration in the marginal portion was higher than those of the inner portion and peel. 3) The outer most cells of the cortex were filled with polyhedronous oxalic acid crystals, that were smaller than those of other crops. There was distasteful influence on fruit quality following calcium-chelate treatment. These findings suggested that the calcium-chelate application treatment is an effective method of extending the postharvest life of carambola fruit.
