Effects of 1-methylcylopropene (1-MCP) and Modifed Atmopshere Packing (MAP) on postharvest browning and microbial growth of loquat fruit

Abstract

Champagne de Grasse loquat fruits were initially treated with 0 (control), 312.5 ppb and 625 ppb of 1-methylcylopropene (1-MCP) for 6 h at 20 degrees C. After 6 h, treated fruits were divided into the two main groups: within the first main group, 1-MCP treated fruits were placed in Modifed Atmopshere Packing (MAP) and stored for 12 days at 5 degrees C with 90% of relative humidity (RH). Control fruits without exposure to 1-MCP were placed in MAP and maintained under the identical storage conditions. Within the second main group, 1-MCP treated fruits were subjected to two different storage temperatures. The first were placed in trays and then kept for 12 days of storage at 5 degrees C with 90% of RH and the second group was stored for 9 days at 20 degrees C with 60% of RH. Similarly, the control not subjected to 1-MCP treatment was maintained under the same condition. Treatment groups and control were examined for the following parameters: the flesh fruit firmness, total soluble solid (TSS) content, titratable acidity (TA), color value (L and Chroma), browning index and microbial quality. Unpacked 1-MCP treatments (312.5 and 625 ppb) improved the storage quality of loquat fruits, but, the most efficient treatment was achieved with 625 ppb of 1-MCP. However, the combination of 1-MCP and MAP revealed a better effect on maintaining the fruit quality as indicated by the delay of softening, deterioration rates, TA, browning rate and the significant inhibition of total aerobic mesophiles, psychrotrophic aerobic bacteria, yeast and molds during the whole storage period. The results indicated that the most efficient application in all treatments was obtained using the combination of 1-MCP (625 ppb) with MAP at 5 degrees C storage.