Crowe Kristi M, Bushway Alfred A, Bushway Rodney J, Davis-Dentici Katherine, Hazen Russell A
Department of Food Science and Human Nutrition, University of Maine, 5735 Hitchner Hall, Orono, ME 04469-5735, USA.
Int J Food Microbiol. 2007 May 1;116(1):25-31. doi: 10.1016/j.ijfoodmicro.2006.12.027. Epub 2007 Jan 16.
Advanced oxidation processes and single chemical oxidants were evaluated for their antimicrobial efficacy against common spoilage bacteria isolated from lowbush blueberries. Predominant bacterial flora were identified using biochemical testing with the assessment of relative abundance using non-selective and differential media. Single chemical oxidants evaluated for postharvest processing of lowbush blueberries included 1% hydrogen peroxide, 100 ppm chlorine, and 1 ppm aqueous ozone while advanced oxidation processes (AOPs) included combinations of 1% hydrogen peroxide/UV, 100 ppm chlorine/UV, and 1 ppm ozone/1% hydrogen peroxide/UV. Enterobacter agglomerans and Pseudomonas fluorescens were found to comprise 90-95% of the bacterial flora on lowbush blueberries. Results of inoculation studies reveal significant log reductions (p< or 5) in populations of E. agglomerans and P. fluorescens on all samples receiving treatment with 1% hydrogen peroxide, 1% hydrogen peroxide/UV, 1 ppm ozone, or a combined ozone/hydrogen peroxide/UV treatment as compared to chlorine treatments and unwashed control berries. Although population reductions approached 2.5 log CFU/g, microbial reductions among these treatments were not found to be significantly different (p< or 5) from each other despite the synergistic potential that should result from AOPs; furthermore, as a single oxidant, UV inactivation of inoculated bacteria was minimal and did not prove effective as a non-aqueous bactericidal process for fresh pack blueberries. Overall, results indicate that hydrogen peroxide and ozone, as single chemical oxidants, are as effective as AOPs and could be considered as chlorine-alternatives in improving the microbiological quality of lowbush blueberries.
对高级氧化工艺和单一化学氧化剂针对从矮丛蓝莓中分离出的常见腐败细菌的抗菌效果进行了评估。使用生化测试鉴定主要细菌菌群，并使用非选择性和鉴别性培养基评估相对丰度。评估用于矮丛蓝莓采后处理的单一化学氧化剂包括1%过氧化氢、100 ppm氯和1 ppm臭氧水溶液，而高级氧化工艺（AOPs）包括1%过氧化氢/紫外线、100 ppm氯/紫外线和1 ppm臭氧/1%过氧化氢/紫外线的组合。发现成团肠杆菌和荧光假单胞菌占矮丛蓝莓细菌菌群的90-95%。接种研究结果显示，与氯处理和未清洗的对照浆果相比，接受1%过氧化氢、1%过氧化氢/紫外线、1 ppm臭氧或臭氧/过氧化氢/紫外线联合处理的所有样品中，成团肠杆菌和荧光假单胞菌的数量均有显著的对数减少（p<或5）。尽管数量减少接近2.5 log CFU/g，但尽管AOPs应具有协同潜力，但这些处理之间的微生物减少并未发现有显著差异（p<或5）；此外，作为单一氧化剂，接种细菌的紫外线灭活作用很小，对于新鲜包装蓝莓而言，作为非水性杀菌工艺并不有效。总体而言，结果表明，过氧化氢和臭氧作为单一化学氧化剂，与AOPs一样有效，在提高矮丛蓝莓的微生物质量方面可被视为氯的替代品。
