Color Evaluation and Sensory Analyses of Beef Subprimals Following Extended Frozen Storage

Thirty-six strip loins and top sirloin butts were collected from USDA Low Choice, “A” maturity carcasses and were assigned to freezing treatment. Subprimals were fabricated into Gluteus medius (GM) and Longissimus lumborum (LL) steaks. Beef steaks were evaluated during a 28-d retail display following freezing as a subprimal (SNGL), subprimal and steak (DBL), or never frozen (CON). Steaks were evaluated in 2 packaging films: standard/traditional rollstock packaging (ROLL) and sodium nitrite-embedded (NIT). Steak color was evaluated every 12 h instrumentally and visually every 24 h. Spoilage organisms, lipid oxidation, and purge loss analyses were conducted on days 0, 14, and 28. Trained sensory analyses were conducted on steaks without display. Color data and purge loss were analyzed using a generalized mixed linear model, while other analyses utilized a mixed model with freezing, packaging, and display as fixed effects. Redness scores of GM and LL were greatest in DBL-NIT steaks on day 0 (P < 0.05); LL in NIT had increased (P < 0.05) redness values compared with ROLL on day 28. The a* values of LL and GM were increased (P < 0.05) in NIT on day 0 and 14 compared with ROLL. Aerobic counts, Enterobacteriaceae, and lactic acid bacteria of GM and LL were increased (P < 0.05) on day 28 compared with 0. In LL steaks, there was a packaging × display interaction with increased (P < 0.05) MDA in ROLL on day 28 compared with the NIT across all timepoints. Initial juiciness was reduced in GM from SNGL compared with CON and DBL (P < 0.05). Juiciness was reduced in SNGL and DBL compared with CON of LL (P < 0.05). Freezing beef subprimals had minimal influences on descriptive sensory attributes. Markers of beef color varied little due to freezing regimen after the first day of display, while NIT improved color performance.