Influence of maturity stage on the effectiveness of 1-MCP treatment of 'Hayward' kiwifruits during storage.

摘要

'Hayward' kiwifruits were harvested at a commercial maturity stage with flesh firmness of 59 N (3.9), soluble solids content (SCC) of 11.5% (0.6), and titratable acidity (TA) of 1.4% (0.03). They were then divided in 3 groups and treated at different time during storage with 0.5 ppm of 1-MCP for 24 h. A first group was immediately treated (firm stage), a second group was stored at 0掳C for 40 days until 1-MCP treatment when a firmness of 36 N (1.9) was reached (intermediate stage), while a third group was stored at 0掳C for 2 months until treatment when a firmness of 25 N (1.6) was reached (soft stage). 1-MCP treated samples at firm stage were stored for 100 days at 0掳C, while fruits at intermediate and soft maturity stages were stored for 80 days, together with the respective untreated control fruits. Initially upon 1-MCP treatment and during storage, firmness, SSC, TA, respiration rate, vitamin C and total phenolic contents, and antioxidant activity were measured. Untreated firm samples showed a severe firmness loss, which, starting from 23% of the initial value at 20 days of storage, reached 44 and 85% after 60 and 80 days of storage, respectively; treated fruits only lost about 20% of initial firmness after 40 days. At the intermediate stage the effect of 1-MCP treatment resulted evident only after 40 days of storage, when treated samples resulted firmer (about 44%) than the control. Also at the soft stage 1-MCP treatment slowed down softening: firmness decreased of 60 and 54% of initial value for control and treated fruits, respectively during the first days of storage. 1-MCP treatment did not affect chemical composition, while it had a significant effect on respiration rate only for fruits of the firm stage.CT XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Postharvest Technology in the Global Market, Lisbon, Portugal.