By Andy Muirhead – Company Microbiologist, ALS Food & Pharmaceutical (UK)
FSA recalls several products containing Brazil nuts due to possible Salmonella contamination
Contaminated Brazil nuts have been responsible for several product recalls by the UK’s Food Standards Agency in the last few days. The recalls have included a dark chocolate muesli bar with Brazils, Fruit and Nut bars containing Brazils, Coco and Hazelnut grain free granola and a brand of Muesli both of which contained Brazil nuts. It has been reported that several people fell ill after eating the fruit and nut cereal bars. The water activity of Brazil nuts will vary over the expected shelf life of the product, but it can be as low as 0.6, which is clearly too low for Salmonella to grow on the product. Salmonella will not actively grow in water activity levels of below 0.92, so this once again this serves as an example of how Salmonella can remain viable and potentially infectious in a microbiologically “hostile” environment.
Peaches recalled in the US and Canada
In another example of the robust ability of this organism, there is currently an outbreak of Salmonella enteritidis across 9 states in America which has affected 68 people which incredibly has been linked to the consumption of whole peaches. Peaches and peach juice has a pH of between 3.4 and 3.6 so once again way below the pH value of 4.2 which is known to inhibit the growth of Salmonella. How the product has become contaminated on such a wide scale has not yet been identified, but the recall notice has now been extended to Peaches distributed to Canada.
Onions recalled due to the presence of Salmonella
To complete this section (if further evidence was needed), there has been news of a recall of onions which have been implicated in an outbreak of Salmonella newport which has affected 867 people in the US and Canada. Onions (and garlic) are well known for their anti-microbial activity due to the presence of various Sulphur compounds, so once again, the survival of Salmonella in this product is testament to its remarkable tenacity to remain viable in unexpected food matrices.