常温下で異なるフィルムのガス透過特性を利用した包装環境がアボカド, パパイア, マンゴー果実の鮮度保持におよぼす影響

抄録

Low-density polyethylene (LDPE), 40μm in thickness, oriented polypropylene (OPP), 20 μm, and oriented polystyrene (OPS), 40 μm, films with different permeability characteristics were used in modified atmosphere packages (MAP) for avocado (Persea americana), papaya (Carica papaya) and mango (Mangifera indica) fruits. The fruits were, respectively, sealed in the packages with a constant surface area and stored for 8 d at 20°C. Concentrations of O₂, CO₂ and ethylene and their changes inside the packages were measured at a specified time interval. For all packages of the fruits, although the steady-state O₂ partial pressure was about 1 kPa, the CO₂ partial pressure was the highest for the OPP packages and the lowest for the OPS packages. The lowest level for the OPS packages was equal to or less than half of that for the OPP packages. On the other hand, the ethylene accumulation for the LDPE packages was markedly decreased to one half that of the OPP and OPS packages, probably due to inhibition caused by the high levels of CO₂ and an increase in ethylene permeability. The higher the respiratory rate and the ethylene production in the fruits were, the more marked this phenomenon was. The relative humidities of the LDPE and OPP packages ranged from 96 to 100% and were higher than that of the OPS packages (90-93%) . It was shown that the appropriate conditions (low O₂ [1-1.5 kPa] and high CO₂ [10-15 kPa] ) for retaining freshness of avocado, papaya and mango fruits were achieved with the LDPE packages.