Reduction of bacterial populations on vacuum-packaged ground beef patties with fumaric and lactic acids

The effects of fumaric and lactic acid on the total numbers of aerobic, psychrotrophic, and coliform bacteria on vacuum-packaged ground beef patties at 0, 1, 3, 5, 7, 10, and 14 days of storage at 4 degrees C were studied. Fumaric acid treatments resulted in greater reductions in microbial growth than lactic acid treatments. When 5.0% fumaric acid was used, the lag phase was prolonged and microbial growth was reduced (P < 0.05), with total aerobic, psychotrotrophic, and coliform populations reaching net maximum growths of only 1.46, 1.44, and 0.98 log units, respectively, after storage at 4 degrees C for 10 days. Increasing the acid concentrations significantly decreased the growth of all microorganisms. The 5.0% lactic acid was the most inhibitory against coliforms, resulting in a 3.88-log unit reduction after 10 days of storage.