Application of multiple antimicrobial interventions for microbial decontamination of commercial beef trim

Commercially produced, irregularly sized (range, 100 to 400 cm(2)), uninocu lated beef trim was treated by a previously optimized multihurdle antimicro bial process under spray system or hot air gun with set-up speed (1 cm/s): W (water wash at 65 psi for five passes) + HW (82 degreesC water at 30 psi for three passes) + HA (510 degreesC air for five passes) + L (2% [vol/vol] room temperature lactic acid wash at 30 psi for three passes). After treat ment, the trim was finely ground, vacuum packaged, and stored at 4 degreesC for up to 20 days. At regular intervals (0, 5, 10, 15, and 20 days of stor age at 4 degreesC), the ground beef was analyzed to measure mesophilic aero bic bacteria (APC), coliforms, psychrotrophic bacteria (PCT), and presumpti ve lactic acid bacteria (PLAB) and compared with the untreated control. The numbers of APC, coliforms, PCT. and BLAB were reduced to nearly nondetecta ble levels immediately after treatment, with significant differences compar ed with the control (P < 0.05), then started to increase after 5 to 10 days of storage at 4<degrees>C. After 20 days, microbial populations of treated ground beef were significantly lower than those of nontreated ground beef for the numbers of APC, coliforms, PCT, and PLAB (P < 0.05), with differenc es of 1.2, 2.4, 1.6, and 1.6 log CFU/g, respectively. Based on microbial re duction and quality aspects, the multihurdle antimicrobial process was iden tified as an effective intervention to reduce coliforms on beef trim.