Heinrich Victoria, Zunabovic Marija, Petschnig Alice, Müller Horst, Lassenberger Andrea, Reimhult Erik, Kneifel Wolfgang
Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life SciencesVienna, Austria; OFI-Austrian Research Institute for Chemistry and TechnologyVienna, Austria.
Department of Food Science and Technology, Institute of Food Science, University of Natural Resources and Life Sciences Vienna, Austria.
Front Microbiol. 2016 Apr 8;7:490. doi: 10.3389/fmicb.2016.00490. eCollection 2016.
As one of the emerging non-thermal technologies, pulsed light (PL) facilitates rapid, mild and residue-free microbial surface decontamination of food and food contact materials. While notable progress has been made in the characterization of the inactivation potential of PL, experimental data available on the tolerance development to the same (homologous) stress or to different (heterologous) stresses commonly applied in food manufacturing (e.g., acid, heat, salt) is rather controversial. The findings of the present study clearly indicate that both the homologous tolerance development against PL as well as the heterologous tolerance development from heat to PL can be triggered in Listeria monocytogenes. Further, conducted kinetic analysis confirmed that the conventionally applied log-linear model is not well suited to describe the inactivation of L. monocytogenes, when exposed to PL. Instead, the Weibull model as well as the log-linear + tail model were identified as suitable models. Transmission electron microscopic (TEM) approaches allow suggestions on the morphological alterations in L. monocytogenes cells after being subjected to PL.
作为新兴的非热技术之一，脉冲光（PL）有助于对食品及食品接触材料进行快速、温和且无残留的微生物表面去污处理。尽管在表征脉冲光的失活潜力方面已取得显著进展，但关于食品制造中常用的相同（同源）应激或不同（异源）应激（如酸、热、盐）耐受性发展的现有实验数据颇具争议。本研究结果清楚地表明，在单核细胞增生李斯特菌中，既可以引发对脉冲光的同源耐受性发展，也可以引发从热应激到脉冲光的异源耐受性发展。此外，进行的动力学分析证实，当单核细胞增生李斯特菌暴露于脉冲光时，传统应用的对数线性模型不太适合描述其失活情况。相反，威布尔模型以及对数线性+尾部模型被确定为合适的模型。透射电子显微镜（TEM）方法有助于了解单核细胞增生李斯特菌细胞在经受脉冲光后的形态变化。
