Thermal and Chemical Treatments To Reduce on Alfalfa () and Broccoli ( var. ) Seeds before and during the Sprouting Process: A Hurdle Approach.

Sprouts are vehicles of foodborne diseases caused by pathogens such as . The aim of this study was to evaluate thermal and chemical treatments applied as a hurdle approach to reduce in alfalfa () and broccoli ( var. ) seeds before and during their germination. Seeds, inoculated and then dried at 55°C for 48 h, were subjected to a chemical treatment and a thermal shock with (i) 75 mM caprylic acid at 70°C for 5 s, (ii) 0.04% CaO at 70°C for 5 s, or (iii) 1% HO at 70°C for 5 s. After each treatment, seeds were immersed in water at 3°C for 5 s. Next, the imbibition process was carried out with 0.016% HO at pH 3.0. Finally, the seeds were transferred to a rotary drum-type germinator and were sprayed with the same chemical solution that was applied before the imbibition process, for 20 s at intervals of 5 min for 40 min at 3 rpm. All chemical treatments reduced at least 5 log CFU/g on both seeds. Germination rates between 90 and 93% were obtained after application of thermal and chemical treatments. was not detected after the imbibition stage when caprylic acid and HO treatments were applied. However, during the germination process of both seeds, counts of >6 log CFU/g were obtained despite all treatments being applied at different stages of the sprouting process. These results demonstrated that thermal and chemical treatments used as a hurdle approach to control on alfalfa and broccoli seeds significantly reduced the pathogen concentration on seeds >5 log but were ineffective to eliminate and to control its growth during the sprouting process. The production of safe sprouts continues to be a major challenge for industry.