Responses of Horticultural Commodities to Low Oxygen: Limits to the Expanded Use of Modified Atmosphere Packaging

Abstract

The application of low oxygen through modified atmosphere packaging (MAP) is a technique used successfully to preserve the visual quality of lettuce and some other commodities. The expansion of use of low O 2 via MAP to preserve quality of most commodities is limited by technical difficulties achieving target O 2 concentrations, adverse physiological responses to low O 2 , and lack of beneficial responses to low O 2 . Low O 2 often is not used simply because the physiological responses governed by the gas are not limiting quality maintenance. For instance, shelf life may be governed by decay susceptibility, which is largely unaffected by low O 2 and may actually be exacerbated by the conditions encountered in hermetically sealed packages. Physiological processes influenced by low O 2 and limit storability are discussed. The interdependence of O 2 concentration, O 2 uptake by the product, and temperature are discussed relative to requirements for packaging films.