Ozone and 1-methylcyclopropene treatments affect quality and the storage life of fresh carrots
J. Song, L. Fan, 0C.F. Forney, P.D. Hildebrand, M.A. Jordan , W.E. Renderos and K. McRae
AISHS Acta Horticulturae 628: 295-301.
2003
บทคัดย่อ
Fresh carrots (Daucus carota L.) were treated with or without 1.0 uL.L-1 1-methylcyclopropene (1-MCP) for 16 hours before storage or after 3 months of storage at 0 oC, and then exposed tom 0, 300, or 1000 nL.L-1 ozone at 10 oC for 0, 1, 2, or 4 days. The carrots were store at 0 oC for up to 6 months. Decay and mold incidence, electrolyte leakage, surface discoloration, and 6-Methoxymellein (6-MM) content in the peel tissue of carrots were evaluated. While no decay of the roots was observed, the incidence of saprophytic mold on the crowns was reduced during the first 2 months of storage, following the 300 nL.L-1 ozone treatments of 1, 2, or 4 days. A similar effect was found on the carrots treated after 3 months. The 1000 nL.L-1 ozone treatment for 2 or 4 days caused severe tissue injury resulting in the highest mold incidence of 65 % after 6 months of storage. The 1000 nL.L-1 ozone also induced a greater rate of electrolyte leakage in the peel and caused surface discoloration. The discoloration index, using a scale of 0 (absent) to 3 (severe), was 1.55 compared to 0.3 for those treated with 300 nL.L-1 ozone. Bitterness, which results from the accumulation of 6-MM, was affected by the concentration of ozone and the treatment time. Treatment of 300 and 1000 nL.L-1 ozone for 4 days induced 6-MM production in carrot peels reaching concentrations as high as 180 and 365 ug.g-1 , respectively. Treatment with 1-MCP effectively prevented bitterness induced by the ozone treatments. 6-MM remained below 150 ug.g-1 in carrots treated with 1-MCP and 1000 nL.L-1 ozone for 4 days.