ABSTRACT
Lactic Acid Bacteria (LAB), and to a lesser extent bifidobacteria, are relatively acid tolerant but, without pH control, the accumulation of lactic acid ultimately influences their physiology and microbes cease to grow due to autoacidification rather than depletion of nutrients. The technique most applied at the industrial level for dehydration of LAB is freeze-drying. Unfortunately, LAB and most probiotics, excluding Bacillus and Saccharomyces strains, acidify the medium, which is a challenge for manufacturers. Batch and fed-batch fermentations are the most common processes used in the industry for the production of biomass of LAB and bifidobacteria. The reconstitution of dried cultures may greatly affect not only the survival but also the activity of the bacteria, which is of most concern for LAB used as starters. A slow rate of rehydration, carried out at the optimal growth temperature of the culture being rehydrated, is preferred.
