Among food ingredients, concentrates of lactic acid bacteria are widely used as starters for producing cheeses, fermented milks, meats, vegetables and beneficial health products (probiotics). The first objective of this study was to identify environmental hotspots of the production system of lactic acid bacteria concentrates. The second was to compare the impacts of the two scenarios of stabilization (freezing vs. freeze-drying). To fulfill these objectives, Life Cycle Assessment was performed. Since production processes damage lactic acid bacteria, the impact scores were weighted by the quality of the bacteria, i.e., their physiological state, to obtain meaningful comparisons. Storage and fermentation were the hotspots when bacteria were stabilized by freezing, whereas fermentation and freeze-drying were the hotspots when bacteria were stabilized by freeze-drying. By comparing different storage devices (laboratory vs. walk-in freezers), it was revealed that the device scale was a critical choice when storage was a hotspot. Surprisingly, no benefit was obtained by increasing the storage temperature of freeze-dried products from −20 °C to ambient temperature due to the high bacteria quality loss in such storage conditions. The scenario comparison (frozen vs. freeze-dried bacteria) highlighted the dependence of the results on storage time. The most eco-friendly scenario was frozen bacteria for storage periods of less than 2 months, whereas it was freeze-dried bacteria for storage periods of more than 7 months. Between 2 and 7 months, the conclusion depended on the indicators considered. This study demonstrated improvement options for the processes, including the energy efficiency of freeze-drying and the efficient use of steam and water, as well as optimized cleaning procedures for fermentation. It also highlighted the environmental benefit that could be obtained if the quality of the bacteria could be more efficiently preserved during freeze-drying and storage. This study provides valuable information concerning the preservation of microorganisms and the use of the cold chain.

在食品成分中，乳酸菌浓缩物被广泛用作生产奶酪，发酵乳，肉，蔬菜和有益健康产品（益生菌）的起始剂。这项研究的第一个目标是确定乳酸菌浓缩物生产系统的环境热点。第二个是比较两种稳定方案（冷冻与冷冻干燥）的影响。为了实现这些目标，进行了生命周期评估。由于生产过程会破坏乳酸菌，因此对影响得分进行权衡是根据细菌的质量（即它们的生理状态）来进行有意义的比较。冷藏是细菌稳定储存和发酵的热点，而发酵和冷冻干燥是通过冷冻干燥稳定细菌的热点。通过比较不同的存储设备（实验室用冷冻机与步入式冷冻机），可以发现，当存储成为热点时，设备规模是至关重要的选择。出人意料的是，由于在这种储存条件下细菌质量损失很大，因此将冷冻干燥产品的储存温度从-20°C升高到环境温度无法获得任何益处。方案比较（冷冻细菌与冷冻干燥细菌）强调了结果对存储时间的依赖性。最环保的方案是冷冻细菌的储存时间少于2个月，而冷冻细菌的储存时间超过7个月。在2到7个月之间，结论取决于所考虑的指标。这项研究证明了该工艺的改进选择，包括冷冻干燥的能源效率以及蒸汽和水的有效利用，以及优化的发酵清洁程序。它还强调了如果在冷冻干燥和储存过程中可以更有效地保存细菌的品质，可以获得环境效益。这项研究提供了有关微生物保存和冷链使用的有价值的信息。它还强调了如果在冷冻干燥和储存过程中可以更有效地保存细菌的品质，可以获得环境效益。这项研究提供了有关微生物保存和冷链使用的有价值的信息。它还强调了如果在冷冻干燥和储存过程中可以更有效地保存细菌的品质，可以获得环境效益。这项研究提供了有关微生物保存和冷链使用的有价值的信息。