Profile and activity of the bacterial biota of ground beef held from freshness to spoilage at 5-7°C

Four samples of fresh ground beef were stored aerobically and held at 5-7 degreesC for up to 28 days. Although one sample initially yielded 21 different genera of bacteria while two others yielded only seven, all four spoiled essentially in the same way as assessed by aerobic, psychrotrophic, and Gram-negative counts, and by extract-release volume (ERV) and pH values. Pseudomonas spp. was dominant in the spoilage of all samples. As to why this group is so consistently associated with the low-temperature aerobic spoilage of fresh meats, it is hypothesized that they possess the capacity to form a biofilm and that quorum sensing is involved in the overall biofilm forming and functioning processes. (C) 2003 Elsevier Science B.V. All rights reserved.