The residual concentration of CO2 and O2 in the headspace of the packages was assessed for each of the three treatments at seven-day intervals. A constant increase in the percentage of CO2 and a simultaneous reduction in the O2 concentration were noted for the vacuum treatment (Fig. 1), an environment that enabled the development of anaerobic microorganisms. This behavior occurred likely due to the consumption of O2 by muscle respiration, which is higher in the first days following the slaughter and which decreases during the storage period and also due to microbial metabolism, which increases during storage