QUALITY MAINTENANCE OF 'FUYU' PERSIMMON IN COLD STORAGE BY COMBINING 1-MCP AND MODIFIED ATMOSPHERE

This study examined the effects of ethylene action inhibitor 1-MCP (1-methylcyclopropene). MA (modified atmosphere) and ethylene oxidant KMnO4, (potassium permanganate) on the quality of 'Fuyu' persimmon fruit after cold storage. The factors 1-MCR MA and KMnO4, were combined in four manners corresponding to the following treatments: T-1) Control + MA + KMnO4, T-2) 1-MCP + MA + KMnO4,T-3) 1-MCP + MA, and T-4 ) 1-MCP + AA (AA = atmosphere of air). Mature-firm fruit with predominant yellow color were harvested from seven commercial orchards in the northeast of Rio Grande do Sul State. Some Of fruit were exposed to 0.3 mu L L-1 of 1-MCP for 12 h in 24 h after the harvest. After that, fruit were stored in AA or MA induced by polyethylene bags (0.04 mm thick), by 20,40, 60 or 80 days at -0.1 +/- 0.8 degrees C. Two pellets of 8.5 g alumina-KMnO4 were added into the polyethylene bags of treatments one and two before they were sealed. Fruit were analyzed after 0, 3, 6 or 9 days of shelf in AA at 22 +/- 1 degrees C. 1-MCP treatment delayed flesh softening, but did not consistently affect the development of skin disorders (lined dark dots and black spots) on fruit stored in MA containing KMnO4. However, the incidence of skin disorders on 1-MCP treated fruit stored in MA was significantly less than that of 1-MCP treated fruit stored in AA. There were additive effects of 1-MCP and MA on the retention of firmness and on the reduction of chilling injury appeared by the formation of firm gel texture of flesh and translucent stains on the skin. The use of KMnO4 did not improve the retention of fruit quality when treated with 1-MCP and stored in MA. The development of skin disorders was orchard- and storage period-dependent. However, the benefits of 1-MCP and MA combination on the reduction of these disorders and fruit softening were consistent in all orchards. The results indicate that 1-MCP and MA combination is an effective tool to delay the deterioration of 'Fuyu' persimmon fruit during and after cold storage.