Effect of Ionic Irradiation Acidic Electrolyzed Water and Ultrasound On the Germination of Alfalfa and Broccoli Seeds

Effect of ionic irradiation, acidic electrolyzed water, and ultrasound on the germination of alfalfa and broccoli seeds

2005 IFT Annual Meeting, July 15-20 – New Orleans, Louisiana

Session 36E, Fruit & Vegetable Products: General

H. J. KIM1, H. Feng1, and M. M. Kushad2. (1) Dept. of Food Science and Human Nutrition, Univ. of Illinois, Urbana-Champaign, 1304 W. Pennsylvania Ave., 382-Q Agricultural Engineering Science Bldg., MC-642, Urbana, IL 61801, (2) Dept. of Natural Resources and Environmental Sciences, Univ. of Illinois, Urbana-Champaign, 1201 W. Gregory Dr., 279 ERML, Urbana, IL 61801

Vegetable seed sprouts, such as alfalfa, broccoli, mung bean, and radish, are commonly consumed raw in salads and sandwiches because of their nutritional value. However, sprouts have been implicated in a number of foodborne disease outbreaks. Sprout producers have attempted to disinfect seeds before germination since contamination of sprouts is generally associated with contaminated seeds. Effective and environmentally safe seed decontamination methods are needed for this purpose. This study was undertaken, with alfalfa and broccoli seeds, to determine the optimum conditions for ionic irradiation (IR), Acidic Electrolyzed Water (AEW) and ultrasound (US) treatments using germination as a criterion. Before germination test, alfalfa and broccoli seeds were treated with IR at 0 to 12 kGy, AEW at 4, 23, and 55o C for 2 to 60 min and two types of US units at 23 and 55o C for 30 sec to 30 min. The germination percentage was determined by placing 100 treated seeds on water-saturated filter paper in sterile Petri dishes. After 3 days at 24o C, the number of germinated seeds was counted. Germination percentage decreased with treatment time in all experiments. Seeds treated at 55o C for over 10 min poorly germinated even for the control. Germination of AEW treatment at 4 and 23o C was comparable to control for both seed varieties. However, seeds treated with AEW at 55o C had slightly higher germination percentage than the control. US treatment decreased germination at both 23 and 55o C compared to the control. Seeds subjected to ultrasound treatment in a cleaning tank have lower germination rate. Decrease in germination for the IR treatment was not observed until the dose was greater than 4 kGy. Broccoli seeds appeared to be more resistant to IR treatment. The operation conditions corresponding to acceptable germination for the three disinfection treatments can be used in microbial inactivation tests.