Kumar M, Hora R, Kostrzynska M, Waites W M, Warriner K
Department of Food Science, University of Guelph, Guelph, Ontario, Canada.
J Food Prot. 2006 Jul;69(7):1571-8. doi: 10.4315/0362-028x-69.7.1571.
The efficacy of a stabilized oxychloro-based food grade sanitizer to decontaminate seeds destined for sprout production has been evaluated. By using mung bean seeds as a model system, it was demonstrated that the sanitizer could be used to inactivate a five-strain cocktail of Escherichia coli O157:H7 or Salmonella introduced onto beans at 10(3) to 10(4) CFU/g. Salmonella was more tolerant to stabilized oxychloro than was E. coli O157:H7, with sanitizer levels of >150 and >50 ppm, respectively, being required to ensure pathogen-free sprouts. The decontamination efficacy was also found to be dependent on treatment time (>8 h optimal) and the seed-to-sanitizer ratio (>1:4 optimal). Stabilized oxychloro treatment did not exhibit phytotoxic effects, as germination and sprout yields were not significantly (P > 0.05) different as compared with untreated controls. Although human pathogens could be effectively eliminated from mung beans, the aerobic plate count of native microflora on sprouts grown from treated seed was not significantly (P > 0.05) different from the controls. The diversity of microbial populations (determined through 16S rRNA denaturing gradient gel electrophoresis analysis) associated with bean sprouts was not significantly affected by the sanitizer treatment. However, it was noted that Klebsiella and Herbasprillum (both common plant endophytes) were absent in sprouts derived from decontaminated seed but were present in control sprouts. When a further range of seed types was evaluated, it was found that alfalfa, cress, flax, and soybean could be decontaminated with the stabilized oxychloro sanitizer. However, the decontamination efficacy with other seed types was less consistent. It appears that the rate of seed germination and putative activity of sanitizer sequestering system(s), in addition to other factors, may limit the efficacy of the decontamination method.
已评估了一种稳定的氧氯基食品级消毒剂对用于芽苗生产的种子进行去污的效果。以绿豆种子作为模型系统，结果表明该消毒剂可用于灭活接种在豆子上、浓度为10(3)至10(4) CFU/g的大肠杆菌O157:H7或沙门氏菌的五菌株混合菌液。沙门氏菌对稳定的氧氯比大肠杆菌O157:H7更具耐受性，分别需要>150 ppm和>50 ppm的消毒剂水平才能确保芽苗无病原体。还发现去污效果取决于处理时间（最佳>8小时）和种子与消毒剂的比例（最佳>1:4）。稳定的氧氯处理未表现出植物毒性作用，因为与未处理的对照相比，发芽率和芽苗产量没有显著差异（P>0.05）。虽然人类病原体可从绿豆中有效消除，但用处理过的种子培育出的芽苗上天然微生物群的需氧平板计数与对照相比没有显著差异（P>0.05）。消毒剂处理对与豆芽相关的微生物种群多样性（通过16S rRNA变性梯度凝胶电泳分析确定）没有显著影响。然而，值得注意的是，来自去污种子的芽苗中没有肺炎克雷伯菌和草螺菌（均为常见的植物内生菌），而对照芽苗中存在这些菌。当评估更多种类的种子时，发现苜蓿、水芹、亚麻和大豆可用稳定的氧氯消毒剂进行去污。然而，对其他种子类型的去污效果不太一致。除其他因素外，种子发芽率和消毒剂螯合系统的假定活性似乎可能限制了去污方法的效果。
