Tubes for Modified Atmosphere Packaging of Fresh Fruits and Vegetables: Effective Permeability Measurement

Tubes can serve as mediators of gas exchange between the atmosphere inside an impermeable modifiedpackage and the surrounding atmosphere. Gas permeabilities through different size tubes (diameter: 0.0065, 0.010, 0.012and 0.016 m; length: 0.005, 0.010, 0.015, 0.020, 0.022, 0.030, 0.040 m) were measured at 1.5C, 7C, and 19C. It wasfound that gas permeabilities through tubes were not significantly affected by temperature in the range tested; howevertube diameter and length did affect gas permeability. An increase in tube diameter and/or decrease in tube length causedan increase in gas permeability. A regression model relating permeability to tube diameter and length was developed.Oxygen permeability was always greater than carbon dioxide permeability for the same tube dimensions, andpermeability ratios (K*B /K*A ) of tubes were found to be between 0.72 and 0.98.