Positive effect of combing high pressure and biopreservation treatments on lowering the bacterial dynamics growth during storage of diced cooked ham with reduced nitrite salt

We investigated the combined effect of biopreservation and high pressure treatment on bacterial communities of diced cooked ham prepared with diminished nitrite salt. First bacterial communities of dice cooked ham from local supermarkets sampled near the use by date were determined. The four samples studied showed a relative low diversity, characterized by two samples dominated by proteobacteria while in two other firmicutes, essentially Lactobacillus and Leuconostoc were dominant. Sterile diced cooked ham, prepared with half dose of nitrite were inoculated with two proteobacteria rich microbiota collected from ham and a Lactococcus lactis protective strain. Hams were then treated at 500 MPa for 5 minutes and bacterial dynamics was monitored during storage at 8 degrees. When applied alone, none of the treatment stabilized durably the hams. However, the combination of biopreservation and high pressure treatment were more efficient, with L. Lactis becoming dominant till day 31 of storage. However, this effect was depending on the nature of the initial contaminants, showing that use of biopreservation and high pressure treatment as an alternative to nitrite reduction for ensuring cooked ham microbial safety merits attention but still requires improvement.