Purpose: This study investigated the effect of hot water (HW) and peroxyacetic acid (PAA) to inactivate Salmonella in alfalfa, clover, and radish seeds prior to germination.
Methods: Commercially purchased alfalfa, clover, and radish seeds were inoculated with a four serotype cocktail of Salmonella enterica. HW treatment (5 s) followed by PAA treatment at various concentration (30, 60, and 80 ppm) for different time intervals (2, 4, and 6 min) were applied to Salmonella inoculated seeds. Enumeration was performed using XLD agar. Data were analyzed using one-way ANOVA.
Results: Applied treatments of HW and PAA did not affect the rate of seed germination. Among three different types of seeds, these treatments were found to be the most effective in alfalfa seeds. HW alone was able to reduce three log CFU/g while additional treatment with PAA at 60 and 80 ppm for four and six minutes was able to reduce five log CFU/g in alfalfa seeds. However, for clover and radish seeds, treatment with HW and PAA resulted in an average microbial reduction of 3.67 log CFU/g and 1.87 log CFU/g, respectively, with no significant difference among the treatments. These results indicated that effect of PAA in combination with HW treatment is highly dependent on the type of seeds.
Significance: Our data suggested that sequential treatments of HW and PAA could be an effective measure in reducing microbial load in alfalfa seeds intended for sprout production.