Department of Chemical Engineering, KU Leuven, Leuven, Belgium.
Department of Food Biosciences, Teagasc - Irish Agriculture and Food Development Authority, Carlow, Ireland.
J Appl Microbiol. 2018 Jul;125(1):16-35. doi: 10.1111/jam.13751. Epub 2018 Apr 16.
Despite the constant development of novel thermal and nonthermal technologies, knowledge on the mechanisms of microbial inactivation is still very limited. Technologies such as high pressure, ultraviolet light, pulsed light, ozone, power ultrasound and cold plasma (advanced oxidation processes) have shown promising results for inactivation of micro-organisms. The efficacy of inactivation is greatly enhanced by combination of conventional (thermal) with nonthermal, or nonthermal with another nonthermal technique. The key advantages offered by nonthermal processes in combination with sublethal mild temperature (<60°C) can inactivate micro-organisms synergistically. Microbial cells, when subjected to environmental stress, can be either injured or killed. In some cases, cells are believed to be inactivated, but may only be sublethally injured leading to their recovery or, if the injury is lethal, to cell death. It is of major concern when micro-organisms adapt to stress during processing. If the cells adapt to a certain stress, it is associated with enhanced protection against other subsequent stresses. One of the most striking problems during inactivation of micro-organisms is spores. They are the most resistant form of microbial cells and relatively difficult to inactivate by common inactivation techniques, including heat sterilization, radiation, oxidizing agents and various chemicals. Various novel nonthermal processing technologies, alone or in combination, have shown potential for vegetative cells and spores inactivation. Predictive microbiology can be used to focus on the quantitative description of the microbial behaviour in food products, for a given set of environmental conditions.
尽管新型热学和非热学技术不断发展，但微生物失活动力学的知识仍然非常有限。高压、紫外线、脉冲光、臭氧、功率超声和冷等离子体（高级氧化工艺）等技术已显示出对微生物失活的有希望的效果。常规（热）与非热、或非热与另一种非热技术相结合，大大增强了失活动力。非热过程与亚致死温和温度（<60°C）相结合提供的关键优势可以协同失活微生物。当微生物细胞受到环境压力时，它们可能会受到伤害或死亡。在某些情况下，细胞被认为失活，但可能只是亚致死伤害，导致它们恢复，如果伤害是致命的，则导致细胞死亡。当微生物在加工过程中适应压力时，这是一个主要问题。如果细胞适应某种压力，它与对其他后续压力的增强保护有关。在微生物失活过程中最引人注目的问题之一是孢子。它们是微生物细胞最具抗性的形式，并且相对难以通过包括热灭菌、辐射、氧化剂和各种化学物质在内的常见失活技术失活。各种新型非热处理技术单独或结合使用，已显示出对营养细胞和孢子失活的潜力。预测微生物学可用于专注于给定环境条件下食品中微生物行为的定量描述。
