The market for freeze-dried lactic acid bacteria (LAB) starter cultures is constantly growing (~8 %/year) due to the increasing popularity of fermented foods and probiotics. However, many strains exhibiting interesting functionalities present low viability recovery after freeze-drying and insufficient long-shelf stability to be successfully commercialized. The stabilization steps of the manufacturing process of bacterial concentrates (freezing, freeze-drying, storage) induce several types of stresses (thermal, osmotic, mechanical, oxidative), which lead to cell injury and may cause loss of viability and functionality. Bacterial degradation can be minimized by pre-adapting bacteria during fermentation, adding protective molecules and applying favourable operating conditions during stabilization[1], but the results are variable and highly strain-dependent. A better understanding of the preservation and degradation mechanisms appears essential for rationalizing the choice of molecules and process conditions. Moreover, since freeze-drying is a high-cost and energy-intensive process, the preservation of LAB starters needs to be revisited integrating product quality, process efficiency and environmental impact to propose sustainable stabilization processes. In this context, this presentation aims to share the strategies and tools developed in the frame of a European project to identify stress mechanisms, and sites of cell damage and improve the dehydration process conditions.