Allen Brent, Wu Jiangning, Doan Huu
Department of Chemistry, Biology and Chemical Engineering, Ryerson University, Toronto, Ontario, Canada.
J Environ Sci Health B. 2003 Sep;38(5):617-30. doi: 10.1081/PFC-120023519.
The use of gaseous ozone as a fungicide to preserve stored barley was studied. The effects of the following operating parameters on the fungicidal efficacy of ozone were examined: 1) the applied ozone dose, 2) ozonation time, 3) water activity of barley, and 4) temperature of barley. The effect of ozonation on germination of barley was also investigated. The experimental results showed that ozone was very effective in inactivation of fungi associated with the barley regardless of whether the fungi were in the forms of spores or mycelia. However, the mycelia were less resistant to ozone. With 5 minutes of ozonation, 96% of inactivation were achieved for spores as well as for mixtures of spores and small amount of mycelia by applying 0.16 and 0.10 mg of ozone/(g barley) x min, respectively. In addition, for sealed storage silos, inactivation of fungi continued when the ozone-containing gas was held inside the silos following a continuous ozone supply. The experimental results also revealed that increases in water activity and temperature of barley enhanced the fungicidal efficacy of ozone. Results of this study also indicated that the inactivation processes could be controlled by simply monitoring the exit ozone from the reactor instead of performing the time-consuming microbial examination. This finding would make the application of ozone in the preservation of cereal grains easier, simpler, and more practically applicable. The experimental results demonstrated that although ozonation above certain strength may reduce barley germination, inactivation of fungi was achieved with ozonation strengths far below the critical point.
研究了使用气态臭氧作为杀菌剂来保存储存的大麦。考察了以下操作参数对臭氧杀菌效果的影响：1）施加的臭氧剂量；2）臭氧化时间；3）大麦的水分活度；4）大麦的温度。还研究了臭氧化对大麦发芽的影响。实验结果表明，无论真菌是以孢子还是菌丝体的形式存在，臭氧对与大麦相关的真菌的灭活都非常有效。然而，菌丝体对臭氧的抵抗力较弱。通过分别施加0.16和0.10毫克臭氧/（克大麦）×分钟进行5分钟的臭氧化处理，孢子以及孢子与少量菌丝体的混合物的灭活率均达到96%。此外，对于密封的储存筒仓，在持续供应臭氧后，当含臭氧的气体留在筒仓内时，真菌的灭活仍在继续。实验结果还表明，大麦水分活度和温度的升高增强了臭氧的杀菌效果。本研究结果还表明，灭活过程可以通过简单地监测反应器出口的臭氧来控制，而无需进行耗时的微生物检测。这一发现将使臭氧在谷物保存中的应用更加容易、简单且更具实际应用性。实验结果表明，虽然超过一定强度的臭氧化可能会降低大麦发芽率，但在远低于临界点的臭氧化强度下就能实现真菌的灭活。
