Jiang Yunbin, Sokorai Kimberly, Pyrgiotakis Georgios, Demokritou Philip, Li Xihong, Mukhopadhyay Sudarsan, Jin Tony, Fan Xuetong
Key Laboratory of Food Nutrition and Safety (Tianjin University of Science and Technology), Ministry of Education, Tianjin 300457, China.
U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038, USA.
Int J Food Microbiol. 2017 May 16;249:53-60. doi: 10.1016/j.ijfoodmicro.2017.03.004. Epub 2017 Mar 10.
The purpose of this study was to investigate the efficacy of aerosolized hydrogen peroxide in inactivating bacteria and maintaining quality of grape tomatoes, baby spinach leaves and cantaloupes. Stem scars and smooth surfaces of tomatoes, spinach leaves, and cantaloupe rinds, inoculated with Escherichia coli O157:H7, Salmonella Typhimurium and Listeria innocua, were treated for 45s followed by additional 30min dwell time with hydrogen peroxide (7.8%) aerosols activated by atmospheric cold plasma. Non-inoculated samples were used to study the effects on quality and native microflora populations. Results showed that two ranges of hydrogen peroxide droplets with mean diameters of 40nm and 3.0μm were introduced into the treatment chamber. The aerosolized hydrogen peroxide treatment reduced S. Typhimurium populations by 5.0logCFU/piece, and E. coli O157:H7 and L. innocua populations from initial levels of 2.9 and 6.3logCFU/piece, respectively, to non-detectable levels (detection limit 0.6logCFU/piece) on the smooth surface of tomatoes. However, on the stem scar area of tomatoes, the reductions of E. coli O157:H7, S. Typhimurium, and L. innocua were only 1.0, 1.3, and 1.3 log, respectively. On the cantaloupe rind, the treatment reduced populations of E. coli O157:H7, S. Typhimurium and L. innocua by 4.9, 1.3, and 3.0logCFU/piece, respectively. Under the same conditions, reductions achieved on spinach leaves were 1.5, 4.2 and 4.0 log for E. coli O157:H7, S. Typhimurium and L. innocua, respectively. The treatments also significantly reduced native aerobic plate count, and yeasts and mold count of tomato fruits and spinach leaves. Furthermore, firmness and color of the samples were not significantly affected by the aerosolized hydrogen peroxide. Overall, our results showed that the efficacy of aerosolized hydrogen peroxide depended on type of inoculated bacteria, location of bacteria and type of produce items, and aerosolized hydrogen peroxide could potentially be used to sanitize fresh fruits and vegetables.
本研究的目的是调查雾化过氧化氢对葡萄番茄、嫩菠菜叶和哈密瓜中细菌的灭活效果以及对其品质的维持情况。将接种了大肠杆菌O157:H7、鼠伤寒沙门氏菌和无害李斯特菌的番茄、菠菜叶的茎痕处及光滑表面以及哈密瓜外皮，用大气冷等离子体激活的过氧化氢（7.8%）气雾剂处理45秒，随后再停留30分钟。使用未接种的样品来研究对品质和原生微生物菌群数量的影响。结果表明，两种平均直径分别为40纳米和3.0微米的过氧化氢液滴被引入处理室。雾化过氧化氢处理使番茄光滑表面上的鼠伤寒沙门氏菌数量减少了5.0 logCFU/个，使大肠杆菌O157:H7和无害李斯特菌数量分别从初始水平的2.9 logCFU/个和6.3 logCFU/个降至不可检测水平（检测限为0.6 logCFU/个）。然而，在番茄的茎痕区域，大肠杆菌O157:H7、鼠伤寒沙门氏菌和无害李斯特菌的减少量分别仅为1.0 log、1.3 log和1.3 log。在哈密瓜外皮上，该处理分别使大肠杆菌O157:H7、鼠伤寒沙门氏菌和无害李斯特菌数量减少了4.9 logCFU/个、1.3 logCFU/个和3.0 logCFU/个。在相同条件下，菠菜叶上大肠杆菌O157:H7、鼠伤寒沙门氏菌和无害李斯特菌的减少量分别为1.5 log、4.2 log和4.0 log。这些处理还显著降低了番茄果实和菠菜叶的原生需氧平板计数以及酵母菌和霉菌计数。此外，雾化过氧化氢对样品的硬度和颜色没有显著影响。总体而言，我们的结果表明，雾化过氧化氢的效果取决于接种细菌的类型、细菌的位置和农产品的类型，并且雾化过氧化氢有可能用于对新鲜水果和蔬菜进行消毒。
