In the present study, despite the hermeticity of the packaging, maintenance of a 60% CO2 concentration during storage was not possible. The apparent increase followed by the stabilization in the CO2 concentration observed in this study may be associated with CO2 sorption by the beans and small leaks in the packaging, which did not compromise the development of this study aimed at the measurement and periodic replacement of CO2. The phenomenon of CO2 sorption by agricultural products has been reported by other authors (Cofie-Agblor et al., 1995; Shunmugam et al., 2005). Wheat,
canola and barley grains are able to absorb significant amounts of CO2. In addition, the rates of absorption decrease with time until equilibrium is reached between the intra- and inter-granular CO2concentration. This balance depends on the initial CO2 concentration, the type of grain, the temperature and the water content.