This is the main result from Zhao and colleagues at the Center for Food Safety at the University of Georgia from their study into levulinic acid plus sodium dodecyl sulphate as a wash solution to have a practical application for killing food-borne enteric pathogens on uncooked poultry.

Four organic acids (lactic acid, acetic acid, caprylic acid and levulinic acid) and sodium dodecyl sulphate (SDS) were evaluated individually or in combination for their ability to inactivate Salmonella and Escherichia coli O157:H7.

Results from pure culture assays in water with the treatment chemical revealed that 0.5 per cent organic acid and 0.05 to one per cent SDS, when used individually, reduced pathogen cell numbers by 2-log CFU/ml within 20 minutes at 21°C.

The combination of any of these organic acids at 0.5 per cent with 0.05 per cent SDS resulted in a greater than 7-log CFU/ml inactivation of Salmonella and E. coli O157:H7 within ten seconds at 21°C.

A combination of levulinic acid and SDS was evaluated at different concentrations for pathogen reduction on lettuce at 21°C, on poultry (wings and skin) at 8°C, and in water containing chicken faeces or feathers at 21°C. Results revealed that treatment of lettuce with a combination of three per cent levulinic acid plus one per cent SDS for up to 20 seconds reduced both Salmonella and E. coli O157:H7 populations by at least 6.7-log CFU/g on lettuce.

Salmonella and aerobic bacterial populations on chicken wings were reduced by more than 5-log CFU/g by treatment with three per cent levulinic acid plus two per cent SDS for one minute.

Treating water heavily contaminated with chicken faeces with three per cent levulinic acid plus two per cent SDS reduced Salmonella populations by more than 7-log CFU/ml within 20 seconds.

Reference

Zhao, T., P. Zhao and M.P. Doyle. 2009. Inactivation of Salmonella and Escherichia coli O157:H7 on lettuce and poultry skin by combinations of levulinic acid and sodium dodecyl sulfate. Journal of Food Protection, 72 (5), 928-936(9)