Efficacy of Chemical Treatments in Eliminating Salmonella and Escherichia Coli 0157 On Scarified and Polished Alfalfa Seeds

Efficacy of Chemical Treatments in Eliminating Salmonella and Escherichia coli 0157:H7 on Scarified and Polished Alfalfa Seeds
October 2001
Journal of Food Protection: Vol. 64, No. 10, pp. 1489­1495.
Sarah L. Holliday, Alan J. Scouten, And Larry R. Beuchat
Center for Food Safety and Department of Food Science and Technology,University of Georgia, 1109 Experiment Street, Griffin, Georgia 30223-1797,USA
 

Abstract

Alfalfa seeds are sometimes subjected to a scarification treatmentto enhance water uptake, which results in more rapid and uniform germinationduring sprout production. It has been hypothesized that this mechanicalabrasion treatment diminishes the efficacy of chemical treatments used tokill or remove pathogenic bacteria from seeds. A study was done to comparethe effectiveness of chlorine (20,000 ppm), H2O2 (8%), Ca(OH)2 (1%), Ca(OH)2(1%) plus Tween 80 (1%), and Ca(OH)2 (1%) plus Span 20 (1%) treatments inkilling Salmonella and Escherichia coli O157:H7 inoculated onto control,scarified, and polished alfalfa seeds obtained from two suppliers. Theinfluence of the presence of organic material in the inoculum carrieron the efficacy of sanitizers was investigated. Overall, treatment with 1%Ca(OH)2 was the most effective in reducing populations of the pathogens.Reduction in populations of pathogens on seeds obtained from supplier 1indicate that chemical treatments are less efficacious in eliminating thepathogens on scarified seeds compared to control seeds. However, theeffectiveness of chemical treatment in removing Salmonella and E. coliO157:H7 from seeds obtained from supplier 2 was not markedly affected byscarification or polishing. The presence of organic material in the inoculumcarrier did not have a marked influence on the efficacy of chemicals inreducing populations of test pathogens. Additional lots of control,scarified, and polished alfalfa seeds of additional varieties need to betested before conclusions can be drawn concerning the impact of mechanicalabrasion on the efficacy of chemical treatment in removing or killingSalmonella and E. coli O157:H7.