Different responses of 'Snow Giant' and 'Elegant Lady' peaches to fruit maturity and storage temperature

The susceptibility of 'Elegant Lady' and 'Snow Giant' peaches (Prunus persi ca Batsch) to mealiness, leatheriness, flesh browning (FB), and gel breakdo wn (GB) were studied using fruit harvested at different maturity and stored at 0 degrees or 5 degreesC. 'Elegant Lady' developed 10% mealiness and 4% leatheriness without developing leatheriness and GB after four weeks of sto rage at 0 degreesC. At 5 degreesC, however, it had 46% mealiness and 12% FB without developing leatheriness and GB after the same period of storage. F ruit from the last harvest developed more mealiness than those from the two early harvests. 'Snow Giant' developed 92% leatheriness and FB and 68% GB without developing mealiness after five weeks at 0 degreesC. All FB and GB were found in leathery fruit. Fruit from the last harvest developed less le atheriness, FB, and GB than those from the first two harvests. When stored at 5 degreesC, fruit did not develop leatheriness. A low level of mealiness (10%) was found only in fruit from the third harvest. Correlations between mealiness and FB (r(2) = 0.47), leatheriness and FB (r(2) = 0.78), and lea theriness and GB (r(2) = 0.71) were significant. Mealiness was not correlat ed to GB. Leathery fruit from both cultivars produced less ethylene, were f irmer, and contained lower levels of polygalacturonase (PG) activity and hi gher levels of insoluble pectin than mealy and juicy fruit. There were no d iffferences in these measurements between mealy and juicy fruit.