Agricultural Research Station, Virginia State University, Petersburg, VA 23806, USA.
J Food Sci. 2012 Apr;77(4):M206-11. doi: 10.1111/j.1750-3841.2011.02595.x. Epub 2012 Feb 21.
Increased interest in blueberries due to their nutritional and health benefits has led to an increase in consumption. However, blueberries are consumed mostly raw or minimally processed and are susceptible to microbial contamination like other type of fresh produce. This study was, therefore, undertaken to evaluate the efficacy of electrostatic spray of electrolyzed oxidizing (EO) water, UV light, ozone, and a combination of ozone and UV light in killing Escherichia coli O157:H7 on blueberries. A 5-strain mixture of E. coli O157:H7 were inoculated on the calyx and skin of blueberries and then subjected to the treatments. Electrostatic EO water spray reduced initial populations of E. coli O157:H7 by only 0.13 to 0.24 log CFU/g and 0.88 to 1.10 log CFU/g on calyx and skin of blueberries, respectively. Ozone treatment with 4000 mg/L reduced E. coli O157:H7 by only 0.66 and 0.72 log CFU/g on calyx and skin of blueberries, respectively. UV light at 20 mW/cm² for 10 min was the most promising single technology and achieved 2.14 and greater than 4.05 log reductions of E. coli O157:H7 on the calyx and skin of blueberries, respectively. The combination treatment of 1 min ozone and followed by a 2 min UV achieved more than 1 and 2 log additional reductions on blueberry calyx than UV or ozone alone, respectively.
Outbreaks of foodborne illnesses have been associated with consumption of fresh produce. Many methods for removing pathogens as well as minimizing their effect on quality of treated produce have been investigated. UV technology and its combination with ozone used in this study to inactive E. coli O157:H7 on blueberries was found effective. Results from this study may help producers and processors in developing hurdle technologies for the delivery of safer blueberries to consumers.
由于蓝莓的营养价值和健康益处，人们对其兴趣日益浓厚，导致其消费量增加。然而，蓝莓通常是生吃或经过最低限度的加工，像其他新鲜农产品一样容易受到微生物污染。因此，本研究旨在评估静电喷雾电解氧化（EO）水、紫外线、臭氧以及臭氧和紫外线联合处理对蓝莓上大肠杆菌 O157:H7 的杀菌效果。将 5 株大肠杆菌 O157:H7 混合菌接种在蓝莓的花萼和果皮上，然后进行处理。静电 EO 水喷雾对蓝莓花萼和果皮上的大肠杆菌 O157:H7 初始菌数的减少量仅分别为 0.13 至 0.24 和 0.88 至 1.10 log CFU/g。4000mg/L 的臭氧处理仅使蓝莓花萼和果皮上的大肠杆菌 O157:H7 减少 0.66 和 0.72 log CFU/g。紫外线在 20 mW/cm² 下照射 10 分钟是最有前途的单一技术，对蓝莓花萼和果皮上的大肠杆菌 O157:H7 分别实现了 2.14 及以上和大于 4.05 log 的减少。1 分钟臭氧处理后再进行 2 分钟紫外线处理，对蓝莓花萼的杀菌效果比单独使用紫外线或臭氧分别多 1 及 2 个对数级。
食源性疾病的爆发与食用新鲜农产品有关。人们已经研究了许多去除病原体的方法以及尽量减少其对处理过的农产品质量影响的方法。本研究中用于使蓝莓上大肠杆菌 O157:H7 失活的 UV 技术及其与臭氧的结合被证明是有效的。本研究的结果可能有助于生产者和加工者开发更安全的蓝莓输送给消费者的障碍技术。
