Reduction of the native microflora on alfalfa sprouts during propagation by addition of antimicrobial compounds to the irrigation water

Alfalfa and other types of sprouts are known to harbor large populations of native microorganisms. As some of these microbes may be causes of reduced shelf life of the product (plant pathogens and other spoilage organisms) and sprouts may, on occasion, harbor bacteria pathogenic towards humans, the addition of antimicrobial compounds to the irrigation water may be warranted. In this study, we tested the efficacy of several antimicrobial compounds for reducing the native microbial populations on alfalfa sprouts during propagation. These compounds included H2O2, peroxyacetic acid+hydrogen peroxide (Tsunami 100™), acidified NaClO2, NaClO2 (Aquatize™), EDTA, Na3PO4 and NaOCl. When added to the irrigation water at various concentrations, none of the antimicrobial compounds reduced the levels of any class of native microflora by more than 1 log10 without evidence of phytotoxicity.