Microbial and Quality Attributes of Beef Steaks under High-CO Packaging: Emitter Pads versus Gas Flushing.

Over 21 days of cold storage, the quality and microbial composition of beef steaks in response to different high-CO packaging conditions achieved by flushing gas mixtures or embedding gas emitters into the packages were studied. The results revealed that the high levels of CO, achieved by either the gas flushing or the CO emitter pads, effectively controlled the number of aerobic counts. The headspace CO increased quickly in response to using the CO emitter pads, and the meat samples presented different pH levels and surface color (a* and b*) values compared to the samples packaged with the gas flushing technique. Excessive accumulation of gas in the packages that contained CO emitters resulted in package swelling and higher levels of drip loss. The longest overall quality and attractive red color of the meat samples were observed when the packages were initially flushed with the headspace gas mixture containing high levels of oxygen. Overall, using CO emitters for meat packaging can be suggested when a topfilm with proper permeability to O and CO gases is used to regulate the internal CO/O and gas/product ratios.