ABSTRACT
This research characterized the effect of 0.6 and 1.2% acetic and lactic acids applied for 20 and 120 s at a temperature of 1 to 2°C on total colony forming units (CFU) and Escherichia coli counts, and sensory qualities including shear value, expressible moisture, color and sensory panel of retail cuts of beef rib steaks. Microbial inhibition was directly proportional to the concentration and times of treatment with a 1.2% acid treatment for 120 s being the most effective treatment for reducing microbial counts, for both acids. Although there were significant reductions (p <0.05) in bacterial populations, these reductions which had a maximum of 2.0 log, were of questionable practical significance. The inhibitory effect of the acids decreased with storage time, up to 9 days. Treatment with both the acids resulted in paler meat (p <0.05) than the non-treated control. There were no significant differences (p >0.05) in shear values or expressible moisture due to acid treatment. Sensory panels reported only small differences between the samples. These results indicate that an aqueous acetic or lactic acid treatment of retail beef reduced total CFU and E. coli numbers immediately after treatment, but the magnitude was less than 1 log. However, a residual influence was observed so that after 3 and 9 days both acid treatments inhibited total CPU and E. coli growth by up to 2 logs compared with the non-treated control samples.
