2 - Advances in controlled atmosphere storage of fruits and vegetables

Abstract

This chapter is about the controlled atmosphere (CA) packaging technique. CA storage commonly uses low oxygen (O2) levels and high carbon dioxide (CO2) levels in the storage atmosphere combined with refrigeration. In CA storage, inside a food storage room is the gas composition that continually monitors and adapts to maintain the optimum concentration within completely close tolerances. Because CA storage is capital intensive and expensive to operate, it is more appropriate for those foods that are agreeable to long-term storage such as apples, kiwifruit, and pears. CA packaging is the enclosure of food in a gas impermeable package inside which the gaseous environment with respect to CO2, O2, N2, water vapor, and other trace gases has been changed and is selectively controlled to increase shelf life. Considering the definition, there are no CA packaging systems in commercial use. However, using the combination of O2 and ethylene (C2H4) absorbers, together with CO2 release agents in packaging, at least during the early stages of the storage life of the packaged product, could be classified as CA packaging. There are some functions for the generation and maintaining of CA including O2 removal, excess CO2 removal, and addition of air to replace O2 consumed by respiration, removal of C2H4, and in some cases addition of CO2. Selection of the appropriate functions and devices for generating and maintaining CA depends on what horticultural produce is stored and the storage conditions required for each produce. Research has shown that CA storage has positive, negative, and no effect on certain quality aspects of fruits and vegetables, such as physiological disorders, flavor and off-flavor, acidity, C2H4 production, respiration rate, volatile compounds, phytochemical compounds, color, etc. In this chapter all of these effects are discussed comprehensively.