Inhibitory effect of camel milk on Cronobacter sakazakii

The objective of this study was to investigate the behavior of Cronobacter sakazakii in raw and pasteurized camel milk compared with bovine milk at different incubation temperatures. Pasteurized and raw camel milk was inoculated with a cocktail of two strains of C. sakazakii and incubated at 10 degrees C, 25 degrees C, and 37 degrees C to be sampled at 0, 2, 4, 8, and 24 hr. Pasteurized bovine milk was treated similarly and used as a control. Raw and pasteurized camel milk showed more inhibitory effect against C. sakazakii at 25 degrees C than 37 degrees C while there was no effect at 10 degrees C. The inhibition ranged from 0.40 to 1.42 CFU/ml and 0.61 to 1.6 CFU/ml at 25 degrees C, and from 0.40 to 0.92 CFU/ml and 0.40 to 0.80 CFU/ml at 37 degrees C in pasteurized and raw camel milk after 24 hr, respectively, compared with bovine milk. Moreover, the inhibitory effect of pasteurized camel milk against C.sakazakii was more than raw camel milk after 24 hr at the different incubation temperatures which may approve that the natural antimicrobial proteins in camel milk were resistant to pasteurization temperature. Practical applicationDue to the association of Cronobacter sakazakii with powdered infant formula (PIF), controlling methods, therefore, are highly demanded by PIF manufacturers. The inhibitory activities of camel milk against C. sakazakii and nutritional value make camel milk an outstanding candidate to substitute bovine milk as a base of PIF.