Mathematical model for perforation effect on oxygen and water vapor dynamics in modified-atmosphere packages

A mathematical model was developed to study the influence of film perforations on O-2 concentration and relative humidity in the atmosphere in a package containing fresh fruits. The model included equations describing fruit respiration and transpiration as well as permeation of oxygen and water vapor through the perforated film. Closed-system experiments with mango fruit revealed a linear dependence of respiration rate on O-2 concentration. The model allowed analytical computation of the time course of in-package O-2 concentration and relative humidity, and the results were in good agreement with experimentally measured values. Perforations had a much pronounced effect on O-2 concentration than on relative humidity. The model enabled practical predictions for designing modified-atmosphere packaging.