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Factors, including pH, temperature, glucose concentration, and iron compounds, affect the activity of plant myrosinase and, consequently, endogenous glucosinolate degradation. These factors also may affect glucosinolate degradation by bacterial myrosinase. Therefore, this study examined the effect of temperature (4 to 21°C), glucose (0.05 to 1.0%), and iron (10 mM ferrous or ferric) on sinigrin degradation by Salmonellaor Listeria monocytogenescocktails in Mueller-Hinton broth and the effect of sinigrin degradation on bacterial viability. The degradation of sinigrin by both pathogens increased with higher temperatures (21 > 10 > 4°C). Salmonellaand L. monocytogenescocktails hydrolyzed 59.1 and 53.2% of sinigrin, respectively, at 21°C up to 21 days. Both iron compounds significantly enhanced sinigrin degradation by the pathogens. On day 7, sinigrin was not detected when the Salmonellacocktail was cultured with ferrous iron or when the L. monocytogenescocktail was cultured in Mueller-Hinton broth containing ferric iron. In contrast, ferric and ferrous iron inhibited the activity of 0.002 U/ml myrosinase from white mustard by 63 and 35%, respectively, on day 1. Salmonellaand L. monocytogenescocktails were able to degrade >80% of sinigrin at 0.05 and 0.1% glucose; however, 0.25 to 1.0% glucose significantly reduced sinigrin degradation. Although both pathogens significantly degraded sinigrin, the allyl isothiocyanate (AITC) recoverable was ≤6.2 ppm, which is not inhibitory to Salmonellaor L. monocytogenes.It is probable that the gradual hydrolysis of sinigrin to form AITC either did not produce an inhibitory level of AITC or the AITC formed was unstable in the aqueous medium and rapidly decomposed to new compounds that were less bactericidal against the pathogens.