Pennisi Luca, Ferri Gianluigi, Lauteri Carlotta, Di Clerico Daniele, Vergara Alberto
Department of Veterinary Medicine, Post-Graduate Specialization School in Food Inspection "G. Tiecco", University of Teramo, Strada Provinciale 18, 64100 Teramo, Italy.
Next Cooking Generation Srl, 20100 Milano, Italy.
Foods. 2024 Oct 13;13(20):3259. doi: 10.3390/foods13203259.
Among innovative food technologies, ultrasounds have demonstrated physical damages (provided by frequency and intensity factors) on bacterial structures while determining the microbiological stabilization of many foodstuffs. This study tested the efficacy of the thermosonication process on 16 strains belonging to the academic biobank (isolated from swine slaughterhouses). All strains were exposed to focused ultrasounds, generated by the Waveco system (Milan, Italy), with the following settings: 40 KHz coupled with 80 W at different 5 min intervals starting from 5 to 15 ones, and focusing on two different temperatures: 40 °C and 50 °C. After each treatment, all strains were directly plated onto count agars immediately (t0) and after 24 h (t24) of storage at refrigerated temperature. The results showed bacterial reductions by prolonging the sonication treatments until 15 min (i.e., 50 °C for 15 min reduced of 2.16 log CFU/gr the initial loads). In the present in vitro study, the most considerable decrease was observed after 24 h. It meant that strains were lethally damaged at the wall level, confirming the ultrasound bactericidal effect on loads. The present in vitro scientific investigation demonstrates the practical bactericidal effects of thermosonication, highlighting promising applications at the industry level for food microbial stabilization and shelf-life prolongation.
在创新食品技术中，超声波已证明（由频率和强度因素所致）对细菌结构具有物理损伤作用，同时可实现多种食品的微生物稳定化。本研究测试了热超声处理对来自学术生物样本库（从猪屠宰场分离）的16株菌株的效果。所有菌株均暴露于由Waveco系统（意大利米兰）产生的聚焦超声波下，设置如下：40千赫，从5分钟到15分钟以不同的5分钟间隔与80瓦耦合，并聚焦于两个不同温度：40℃和50℃。每次处理后，所有菌株立即（t0）以及在冷藏温度下储存24小时后（t24）直接接种到计数琼脂平板上。结果表明，将超声处理延长至15分钟可使细菌数量减少（即50℃处理15分钟使初始菌量减少2.16 log CFU/克）。在本体外研究中，24小时后观察到最显著的减少。这意味着菌株在细胞壁水平受到致命损伤，证实了超声波对菌量的杀菌作用。本体外科学研究证明了热超声处理的实际杀菌效果，突出了其在食品微生物稳定化和延长保质期方面在工业层面的应用前景。
