Purpose: This study evaluated the effectiveness of a newly designed culture method for the detection of Salmonella in allspice, cinnamon, and oregano.
Methods: Two varieties of each spice were used in the study. Spices were inoculated with Salmonella ser. Montevideo, Typhimurium, or Weltevreden at 1.7 to 3.53 log CFU/25 g. Two sets of 20 samples (25 g) were analyzed using both the new method and the Bacteriological Analytical Manual (BAM) method. For the new method, 225ml of TSB preenrichment broth was added to 25g of allspice or cinnamon, in a sterile Whirl-PakTM filter bag and vigorously shaken for 60 sec manually; the rinsate was transferred to a fresh sterile Whirl-PakTMbag and incubated at 35 ± 2°C for 24 ± 2 h. A 450ml aliquot of TSB was used for oregano because the leaves absorbed too much water. Eighteen separate trials were performed; each consisted of 40 samples.
Results: In the 18 separate trials, with cinnamon, allspice and oregano, the new method outperformed (P < 0.05) the BAM method in 9 trials. In the other 9 trials, there was no significant difference (P > 0.05) between the two methods. When combining data from six trials per spice, the new method detected 81, 90, and 83 positive; the FDA BAM detected 37, 60, and 50 positive of 120 test portions for cinnamon, oregano, and allspice, respectively. The differences were significant (P< 0.05).
Significance: In conclusion, the new method was more sensitive and effective and easier to operate compared to the current FDA BAM method for the detection of Salmonella in allspice, cinnamon and oregano.