Simple determination of the O2 and CO2 permeances of microperforated pouches for modified atmosphere packaging of respiring foods

A procedure permitting the simple determination of the O2 and CO2 permeance of pouches used to pack respiring foods under real conditions is described. It is based on the measurement of the atmosphere changes in pouches filled with a gas mixture whose composition is calculated as a function of the permselectivity of film. The experimental curves (pCO2 and p(21-O2)) versus storage duration are submitted to an exponential regression. The exponential coefficients are directly proportional to the O2 and CO2 permeances of the films. The method is designed for microperforated films (permselectivity close to 1), but can also be used to approximate the permeances of non-perforated films. The large variability of the permeances of the microperforated films is due to the heterogeneity of perforation density and diameter.