Effect of ethanol vapor on growth and toxin production by Clostridium botulinum in a high moisture bakery product

To determine the effect of ethanol vapor on toxin production by Clostridium botulinum, studies were done in English style crumpets (a(w) 8.990, pH 65) challenged with 500 spores/g C. botulinum types A and proteolytic B and pa ckaged in high gas barrier bags [ethanol transmission rate (ETR) 0.21 g/m(2 )/day @ 25C]. Crumpets were packaged in air with either commercially availa ble ethanol vapor generators (Ethicap((R)) 2, 4 or 6G) or cotton wool pads saturated with 2, 4 or 6 g of 95% food grade ethanol and stored at 25C. Tox in was detected in all inoculated control crumpets (0% ethanol) after 5 day s at ambient temperature (25C). Ethicap((R)) 2G delayed toxicity for 10 day s while complete inhibition (>21 days) was observed in all crumpets package d with 4 or dG Ethicap((R)) or with 2, 4 or 6 g of ethanol per pad. However , all crumpets were overtly spoiled by this time. Both headspace ethanol an d absorption of ethanol by crumpets increased as a function of Ethicap((R)) size/weight of ethanol. Based on these preliminary studies, ethanol vapor would appear to be an effective additional barrier to control the growth an d toxin production by C. botulinum in high moisture bakery products and ens ure the safety of these products at ambient temperature.