Reducing Microbial Populations on Beef Tissues: Concentration and Temperature of an Acid Mixture

A mixture of 2% acetic, 1% lactic, 0.25% citric and 0.1% ascorbic acid was applied to beef core samples of muscle inoculated with bacteria. Experimental variables were concentration and temperature of mixed acids and type of microorganism. Overall, an increase in either mixed acids concentration (0 to 3%) or temperature (20 to 70°C) resulted in reductions in counts of about one logi 0 for aerobic bacteria and S. ryphimurium , less than one log 10 for Enterobacteriaceae , and about one‐half log 10 for E. coli. Initial meat surface pH dropped to 4.3 after treatment with 3% mixed acids solution but rose to 5.2 after 24 hr. Overall, this mixture of acids performed about the same as acetic acid or lactic acid under the same conditions.