The microbiological quality of commercial herb and spice preparations used in the formulation of a chicken supreme ready meal and microbial survival following a simulated industrial heating process

The microbiological status of thirty herb and spice preparations used in the manufacture of ready meals was determined. The effect of a simulated manufacturing process with subsequent cold storage was evaluated on spices having highest microbial loads either suspended in water, or added to a ready meal. Total aerobic mesophilic bacteria count indicated that 20% of the spices had >6 log CFU/g. Spore-forming bacteria and thermophiles (2-6 log CFU/g) were detected in 80% of samples. Pseudomonas spp. and Enterobacteriaceae (2-6 log CFU/g) were detected in 33% or 23% of spices, respectively. Molds were detected in 50% of samples (1-3 log CFU/g), while yeasts were detected in two samples only. Bacillus cereus was detected only in samples of marjoram. The simulated manufacturing treatment with subsequent cold storage indicated a degree of bacterial survival with a possible protective effect of the food matrix. Overall, the heat processing steps applied during manufacture of chilled ready meals may not always be sufficient to eliminate the indigenous microflora especially in spices of poor microbiological quality.