Effects of high-oxygen, carbon monoxide modified atmospheres and vacuum packaging on quality of Longissimus thoracis et lumborum steaks from Nellore cows during ageing.

Nellore (Bos indicus) cows play an important role in Brazilian beef production. Here, we investigated whether modified atmosphere packaging (MAP) technology could contribute to improving the quality of Nellore cow steaks. To verify this, steaks obtained from Longissimus thoracis et lumborum (LTL) were stored at 2 °C for 28 days using different packaging systems, with one being vacuum and the others being three MAP systems: 75% O2/25% CO2 (75%O2-MAP), 60% CO2/0.2% CO/39.8% N2 and 40% CO2/0.4% CO/59.6% N2 (0.2%CO-MAP and 0.4%CO-MAP, respectively). Steaks packaged using the CO-MAP showed improved color stability of fresh meat. In turn, the 75%O2-MAP drastically affected the oxidative stability related to proteins and lipids compared to both anaerobic environments (CO-MAP and vacuum). The CO-MAP increased tenderization and ultrastructural changes when compared to the aerobic MAP without affecting pH, collagen or cooking loss, which were influenced by the storage time. In conclusion, MAP technology may improve the quality and appearance of fresh meat originating from Nellore cows, being a promising alternative for the Brazilian beef industry.