Partial oxygen pressure in the range of 5–10 mm of mercury will rapidly convert the myoglobin pigment in meat to metmyoglobin. Therefore, the residual oxygen (O2) requirement for vacuum packaged meat is very strict andmust be below 0.05% after packaging, and essentially zero within 24 h following packaging (Venturini, Contreras, Sarant'Opoulos, & Villanueva, 2006). PVC packaging is used for retail storage ofmeat and is extremely permeable to oxygen. The high oxygen and moisture permeability of PVC function to maintain the desirable bright ‘cherry red oxymyoglobin color’ associated with fresh meat. The VP system involves exhaustion of oxygen from the package and sealing immediately or flushing the package with a single gas or combination of gasses. MAP is defined as packaging of a product in an atmosphere which has had a one-time modification of gaseous composition so that it is different from that of air, which normally contains 78.08% nitrogen, 20.96% oxygen, and 0.03% carbon dioxide (USDHHS USFDA, 2009). Modifications of the package atmosphere could involve changing the composition of the gasses or inclusion of other gasses
such as carbon monoxide (CO).