This experiment was designed to evaluate antimicrobial, quality, and shelf life effects of controlled phase carbon dioxide (CPCO2) on beef trimmings destined for ground beef.
Studies showed 1500 psi CPCO2 for 15 min achieved the highest lethality (P<0.05) in challenged beef trimmings (TR) and ground beef (GR). Total Plate Count (TPC), Generic E. coli (GEC), E. coli O157:H7 (O157), and Salmonella spp. (SS) reached 0.83, 0.96, 1.00, and 1.06 log reductions, respectively. Bacterial reductions in ground beef (GR) were similar to beef trimmings (TR) (P≥0.05). After 5 days of simulated retail display, CIE L* and a*, reflectance (630/580nm) ratios were similar for all treatments (P≥0.05). CIE b* scores after 5 days of display were most acceptable at 1500 CPCO2 (b*, P≥0.05), regardless of the packaging conditions. In cooked patties, CIE L* values were similar (P≥0.05) when comparing packaging conditions within the treatments. After 5 days of refrigerated display, CIE L* values were slightly higher for patties packaged under 100% flushed CO2 (CO2) when compared to aerobic trays (AT). CIE a* and b* values and reflectance ratios exhibited very similar trends, both scores were similar (a*,b*, 630/580, P≥0.05) after simulated retail display for all the treatments. The extent of lipid oxidation, after 5 days of simulated retail display, scored higher in AT than CO2, with the highest values reached at 1500 psi CPCO2 (P<0.05). TBAR values in CO2 patties were able to maintain similar values to the control all throughout refrigerated storage (P≥0.05). Ground beef patties manufactured from treated beef trimmings scored higher values for tenderness (P< 0.05) when compared to non-treated. 750 psi CPCO2 appeared to have worse scores for juiciness, beef flavor intensity or off flavor intensity (P<0.05) than the 1500 psi CPCO2 treatment or the control.
The use of controlled phase carbon dioxide was able to reduce bacterial growth in ground beef patties while maintaining organoleptic properties.