Modified Atmosphere Packaging of Fruits and Vegetables for Extending Shelf-Life: A Review

摘要

Fresh fruits and vegetables being living require oxygen (O_2) for their metabolic processes especially for respiration. Modified-atmosphere packaging (MAP) of fresh produce refers to the technique of sealing actively respiring produce in polymeric film packages to modify the O_2 and CO_2 concentration levels within the package atmosphere necessary to maintain the freshness and extend shelf-life. It is often desirable to generate an atmosphere low in O_2 and high in CO_2 concentration to influence themetabolism of the produce being packaged, or the activity of decay-causing organisms to increase storage life. In addition to atmosphere modification, MAP vastly improves moisture retention, which can have a greater influence on preserving quality. Furthermore, packaging isolates the produce from the external environment and helps to ensure conditions that, if not sterile, at least reduce exposure to pathogens and contaminants and physiological injuries. MAP is a dynamic process during which respiration and permeation takes place simultaneously. Hence MAP design requires the determination of intrinsic properties of the produce, i.e. respiration rate, optimum O_2 and CO_2 gas concentrations, and film permeability characteristics. The objective of MAP design is to define conditions that will create the optimum atmosphere inside the package best suited for extending shelf-life of a given produce with shortest possible time period. This can be done by matching the respiration rate of the packaged producewith the film permeation rate for O_2 and CO_2 gases. The details of review on all these aspects of MAP have been done and presented in the present paper.