Occurrence, quantity and diversity of aerobic spore-forming bacteria in spices and herbs of Tabriz retails

The aims of the present work were to evaluate the contamination rate, quantity and diversity of aerobic spore-forming bacteria in spices and herbs marketed in Tabriz. To this end, randomly 5 specimens from 25 different spices and aromatic herbs (totally 125 samples) were obtained from the groceries and shopping centers in different parts of Tabriz. The samples were analyzed using standard plate count and conventional biochemical assays. Results showed that the highest levels of mesophilic spore-forming bacteria were observed in Turmeric spice with an average of 7.02 ± 0.60 log cfu/g and the lowest amount of these bacteria in Coriander spice with average of 4.15 ± 0.56 log cfu/g was observed. From studied spices, sure with average of 4.73 ± 0.86 log cfu/g and the black pepper with average of 7.20 ± 0.81 log cfu/g had lowest and highest thermophilic spore-forming bacteria, respectively. The highest frequency of mesophilic bacteria was related to Bacillus coagulans. The most thermophilic Bacillus species in studied spices were B. macerans (16.99 %), pantotenticus (15.53%) and cereus (14.7 percent). Bacillus species diversity in studied spices showed that marjoram spice had the greatest number of mesophilic Bacillus species (11 species) and Sumac spice had the highest species of thermophilic Bacillus (10 species) had the. Generally, results showed that most of the spices in Tabriz region had a high microbial load of aerobic spore-forming bacteria; and can be a source of contamination and spoilage in foods that used in their combination.