Dry-aging beef under commercial conditions: effects of low and abuse temperatures on microbial safety and physicochemical parameters

Globally, dry-aged beef is predominantly produced in butcher shops and restaurants under heterogeneous, non-standardized conditions, potentially compromising product safety. This study aimed to evaluate the effects of temperature (0°C, 3°C, and 7°C, replicating deviations frequently encountered in commercial environments) and aging time (0, 10, 20, 30, and 40 days) on microbial safety ( E. coli O157:H7, Listeria sp., and psychrotrophic bacteria) and physicochemical parameters (a w , pH, and color) of dry-aged beef. Samples were dry-aged in chambers with 75% relative humidity and 2.5 m/s air velocity. Microbial counts were measured in both the crust and inner portions. Results demonstrated an interaction between temperature and time for E. coli O157:H7 . At 0°C, counts declined progressively over time, reaching undetectable levels in the inner portion by day 30, whereas at 3°C an initial reduction was followed by recovery, and at 7°C counts increased sharply by day 40. There was also an interaction for Listeria spp. counts. At 0°C, reductions were more pronounced, with levels reaching below detection by day 30. Psychrotrophic bacteria increased in the crust but decreased in the inner portion, reinforcing the protective role of the crust. Physicochemical parameters were also influenced, with higher temperatures accelerating water loss and reducing a w , while 0°C better preserved color stability. To ensure safety and consistency in dry-aging, especially when temperature is the primary control measure, precise environmental regulation is vital. Our findings demonstrate that aging at 0°C optimizes both microbial safety and physicochemical stability, especially in systems lacking additional safety hurdles.