Efficacy of Electrolyzed Water in Eliminating Salmonella Enterica AndMechanism of Enhancing Its Uptake Into Alfalfa Seeds

Efficacyof Electrolyzed Water in Eliminating Salmonella Enterica and Mechanism ofEnhancing its Uptake into Alfalfa Seeds

2002Annual Meeting and Food Expo - Anaheim, California

FoodMicrobiology: Fruits and Vegetables

Session15D, 8:30 AM - 12:00 PM, Sunday, June 16, 2002

Presentation15D-1

S.Stan and M. A. Daeschel.

FoodScience and Technology, Oregon State University, 100 Wiegand Hall, Corvallis, OR97331-6602

Alfalfa sprouts have been implicated in several outbreaks of salmonellosis inthe United States. Disinfection of seeds used for sprouting is difficult sinceseeds may be wrinkled or present cracks that allow bacteria to be trapped withinthe seed, where a water-based disinfectant cannot penetrate.

Therefore, amechanism of enhancing the uptake of the sanitizing agent into the seeds mightimprove the disinfection step. We have hypothesized that exchanging the internalgas of seeds with oxygen results in more absorption of a liquid-baseddisinfectant into the seed. The electrolysis of water containing sodium chlorideimparts a strong oxidizing character to the water collected at the anode andthus may be an effective seed disinfecting agent.

The objectives of this study were to evaluate the effectiveness of electrolyzedwater in killing Salmonella enterica Stanley in an aqueous system and todetermine the effect of the oxygen- exchange procedure on the absorption ofelectrolyzed water into the alfalfa seeds.

Seeds (400 g) were exposed to oxygen at a flow rate of 1.5 liters/min for 1 hourto exchange the internal atmosphere. A control was represented by non-exchangedseeds. Anode electrolyzed (AE) water was obtained through the electrolysis ofwater containing 0.05% NaCL.

Results indicated a higher uptake of electrolyzed water into theoxygen-exchanged seeds as compared to the non-exchanged seeds. A soaking timeof 150 min in electrolyzed water reduced the germination of seeds by 17% while a15 min soaking time did not affect the germination. In an aqueous system,electrolyzed water was found to have a 5 log reduction effect on Salmonellaenterica Stanley after 15 min.

This study suggests that the combination of the oxygen gas -exchange procedurewith the use of AE water may be effective in reducing the population ofSalmonella enterica on alfalfa seeds.