Freezedrying Probiotics

Probiotics – Low energy living bacterial food formulations

Research towards a novel and generic strategy that aims at drastic enhancement of robustness of beneficial bacteria during spray drying and subsequent storage. The strategy employs pulsed electroporation leading to reversible pore formation in the bacterial cell membrane.

In short:

  • There is a market need for probiotics
  • They are usually produced under high energy-consuming drying methods
  • The development of a novel stabilisation approach with spray drying


There is an increasing market for living bacterial food formulations, especially probiotics and starter cultures. Typically these formulations are stabilised by freezing and freeze drying, which are highly energy-consuming drying methods. The much more efficient spray drying process is currently not possible because survival of bacteria during spray drying and subsequent storage is limited.


The objective of this project is the development of a novel stabilisation approach that allows spray drying of living bacterial formulations without high loss of bacterial viability. Not only major energy savings will be achieved by replacing freeze drying by the more energy efficient spray drying, but also major energy savings are realised in the supply chain by avoiding refrigerated transport and storage.


Experimental procedures will be developed for integrated assessment of the new approach making bacteria more robust towards spray drying conditions, which involve both stabilisation and small-scale spray drying experiments. Kinetic models will be developed that describe survival during subsequent pre-culturing, stabilisation, drying and storage. Specifically, the effectiveness of the new stabilisation method will be examined and optimised by studying the influence of operating conditions on efficient stabilisation without loss in viability. After that the stabilised cells will be benchmarked for their robustness towards drying and storage. Viability will be addressed from multiple perspectives, e.g. cell membrane integrity and proliferation behaviour. Scalability of the proposed strategy will be addressed by making a conceptual scaling-up design and predictive modelling tools will be provide optimal guidelines that deliver maximum survival at lowest energy consumption in the processing chain.


This project will provide a major energy-saving route for stabilising living bacterial formulations with introducing the more energy efficient spray drying (40% lower energy consumption per kg evaporated water and ~10 times lower total costs compared to freeze drying) and avoiding the need for refrigerated transport. Moreover, the availability of dried living bacterial ingredients expands the possibility for new products with increased shelf-life and thus increased profit and market share in the rapid growing market of probiotics and infant formula for the involved industrial end users.

Read more on our Drying & Dewatering program

Acknowledgement & partners

This project is co-funded by TKI-E&I with the supplementary grant 'TKI- Toeslag' for Topconsortia for Knowledge and Innovation (TKI’s) of the Ministry of Economic Affairs and Climate Policy.