Bacterial populations response to surface flaming in beef trim destined for retail markets

Frozen, vacuum packaged semitendinosus muscles, from "cull" cows were used as beef trim. Meat was tempered at 0°C for 48 h with half of the muscles trimmed of all visible fat while the remainder were allowed to retain all external fat. Muscles were sliced into 1.27 cm² wide strips, with the length of the strips determined by the width of the muscle and then tempered at 4.4°C for an additional 12 h. This experiment utilized four treatments, a low and high fat control in which flame was not applied and low and high fat treatments in which 10 seconds of surface flaming was utilized. After treatment, beef trim was ground, formed into patties, and placed in cooler storage for 0, 1, 2, 4, or 8 days. Treatment HFO patties (high fat, no flame) had higher (P<0.01) aerobic-plate-counts (APC) than all other patties. High fat products were shown to display higher (P<0.01) APC than lower fat patties. LFO (low fat, no flame) patties and LF10 (low fat, 10 seconds flame) had similar (P>0.05) psychrotrophic-plate-counts (PPC), however, were lower (P<0.01) than both HFO and HF10 (high fat, 10 seconds flame) patties. Moreover, HF10 patties had less (P<0.01) PPC than did HFO patties. Also, lower fat products showed fewer (P<0.01) PPC than higher fat products. Evaluation of pseudomonas counts (PSU) showed HFO patties to possess more (P<0.01) organisms than all other products. Additionally F10 and LFO, and LF10 and HF10 had similar (p>0.05) values.