Abstract
Modified atmosphere packaging (MAP) is a dynamic system during which respiration and permeation occur simultaneously. Hence factors affecting both respiration and permeation were considered for designing a package. In the design of MA packages for guava (cv. Baruipur) a total of 13 variables were considered. The independent variables includes: weight of fruits, surface area of packaging film, free volume of the package, thickness of the film and permeabilities of film to O2 and CO2 gas. The fixed variables considered were: the surrounding gas composition and temperature, the respiration rates for O2 consumption and CO2 evolution, and the equilibrium gas compositions to be attained in the package so that the fruit's shelf-life is extended. Two types of MA packages, having package size of 19 cm × 19 cm for a fill weight of 1,000 ± 100 g were developed. Packages were designed to accommodate a fill weight range of 0.90-1.10 kg. Various package parameters were optimized to facilitate establishment of dynamic equilibrium at target levels of O2 and CO2 concentration in the package. The storage study of MA packages was performed at 10, 15, 20 and 25 °C temperatures. The performance of film packages was evaluated for their ability to establish equilibrium at target levels and to extend the shelf life of the packaged fruit. The MA packaging system increased the shelf life of guava by 128-200 % compared to the unpacked fruits at various storage temperatures with a quality comparable with the freshly harvested commodity.