Survival of E. coli O157:H7 during manufacture of dry-cured Westphalian ham surface-treated with allyl isothiocyanate or hot mustard powder

BACKGROUND: Escherichia coli O157:H7 can survive commercial manufacture of some uncooked fermented meats. External application of microencapsulated allyl isothiocyanate (AIT) or hot (non-deheated) yellow mustard powder was used to inactivate the pathogen during dry-cured Westphalian ham manufacture. RESULTS: Within 45/80 days, E. coli O157:H7 numbers were reduced 5 log(10) CFU g(-1) by 400 mu g kg(-1) AIT or 60 g kg(-1) mustard powder, but 80 days were required in the untreated control. Mustard powder but not AIT reduced numbers of lactic acid bacteria and staphylococci. Mustard powder or >= 300 mu g kg(-1) AIT inhibited yeasts and moulds but did not affect ham pH or water activity. CONCLUSION: The commercial Westphalian ham process without AIT or mustard powder treatment was validated capable of reducing E. coli O157:H7 5 log(10) CFU g(-1). Surface treatments with >= 300 mu g kg(-1) microencapsulated AIT or 60 g kg(-1) yellow mustard powder reduced the time required for this reduction by 40-50%. AIT volatility from microcapsules or hot mustard powder during application of these compounds may restrict their use in production facilities. (C) 2009 Society of Chemical Industry