Scouten A J, Beuchat L R
Center for Food Safety and Department of Food Science and Technology, University of Georgia, Griffin, 30223-1797, USA.
J Appl Microbiol. 2002;92(4):668-74. doi: 10.1046/j.1365-2672.2002.01571.x.
To determine the effectiveness of combined treatments with chemicals, heat and ultrasound in killing or removing Salmonella and Escherichia coli O157:H7 on alfalfa seeds intended for sprout production.
Alfalfa seeds inoculated with Salmonella or E. coli O157:H7 were treated with ultrasound (38.5-40.5 kHz) in solutions containing 1% Ca(OH)(2), 1% Tween 80, 1% Ca(OH)(2) plus 1% Tween 80, 160 microg ml(-1) Tsunami 200 and 0.5% Fit at 23 and 55 degrees C for 2 and 5 min. Highest reductions were in chemical solutions at 55 degrees C, but seed viability was also reduced compared with treatment at 23 degrees C. Inactivation of Salmonella and E. coli O157:H7 was generally enhanced by simultaneous treatments with ultrasound, chemicals and heat.
Ultrasound treatment, in combination with chemicals and heat, had a modest enhancing effect on the effectiveness of chemicals in killing or removing pathogens on alfalfa seeds. Overall, treatment with 1% Ca(OH)(2) was most effective in killing Salmonella and E. coli O157:H7.
The use of 1% Ca(OH)(2) instead of 20,000 microg ml(-1) chlorine, which is currently recommended as a sanitizer for seeds intended for sprout production in the US, should be considered. Ultrasound treatment of alfalfa seeds containing Salmonella or E. coli O157:H7, in combination with chemical treatment, contributes to achieving greater reductions in populations of these pathogens, thereby reducing the risk of contamination and the presence of pathogens in sprouts produced from these seeds.
确定化学物质、加热和超声联合处理对杀灭或去除用于芽苗菜生产的苜蓿种子上的沙门氏菌和大肠杆菌O157:H7的效果。
接种了沙门氏菌或大肠杆菌O157:H7的苜蓿种子在含有1%氢氧化钙、1%吐温80、1%氢氧化钙加1%吐温80、160微克/毫升“海啸200”和0.5%“菲特”的溶液中，于23℃和55℃下进行超声（38.5 - 40.5千赫兹）处理2分钟和5分钟。在55℃的化学溶液中病原体减少量最高，但与23℃处理相比种子活力也有所降低。沙门氏菌和大肠杆菌O157:H7的失活通常通过超声、化学物质和加热同时处理得到增强。
超声处理与化学物质和加热相结合，对化学物质杀灭或去除苜蓿种子上病原体的效果有适度增强作用。总体而言，用1%氢氧化钙处理在杀灭沙门氏菌和大肠杆菌O157:H7方面最有效。
应考虑使用1%氢氧化钙替代目前美国推荐用于芽苗菜生产种子消毒的20000微克/毫升氯。对含有沙门氏菌或大肠杆菌O157:H7的苜蓿种子进行超声处理并结合化学处理，有助于更大程度地减少这些病原体的数量，从而降低污染风险以及用这些种子生产的芽苗菜中病原体的存在。
