Microbial and Quality Attributes of Beef Steaks under High-CO₂ 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-CO₂ packaging conditions achieved by flushing gas mixtures or embedding gas emitters into the packages were studied. The results revealed that the high levels of CO₂, achieved by either the gas flushing or the CO₂ emitter pads, effectively controlled the number of aerobic counts. The headspace CO₂ increased quickly in response to using the CO₂ 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 CO₂ 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 CO₂ emitters for meat packaging can be suggested when a topfilm with proper permeability to O₂ and CO₂ gases is used to regulate the internal CO₂/O₂ and gas/product ratios.