Intensification of probiotics drying. Spray-drying of Bifidobacteria biosuspension
Special Symposium - EPIC-1: European Process Intensification Conference - 1
EPIC-1: Intensified Plants & Process Integration (IPPI)
Keywords: Intensification, spray-drying of probiotics, mathematical modelling, scale-up
The innovation spray-drying of probiotics considered by the example of Bifidobacteria biosuspension drying has been proposed. The spray-drying can be used as an alternative for vacuum freeze-drying because it allows to intensify heat and mass transfer, to organize continuous process, to produce fine powders with high quality, to delete the powdering stage and as result to increase the sterility of product and reduce operation costs.
The complex of analytical and experimental investigations was carried out:
- Investigation of Bifidobacteria biosuspension as drying object which included the following steps: the heat sensitive analyze, drying kinetics, investigations of biosuspension physical and chemical properties.
- Laboratory scale spray-drying of Bifidobacteria biosuspension with the complex analysis of basic dry powder properties in order to indicate influence of the operation parameters on product quality.
The mathematical model based on heterogeneous media mechanics and non-equilibrium thermodynamics had been developed to choose the optimal operation parameters and to intensify spray-drying. The mathematical model consists of the mass, momentum and energy conservation equations written for gaseous and dispersed phases; equations described drying kinetics of biosuspensions, kinetics of bacteria survival under the high temperatures and osmotic pressure influences; some additional correlations, initial and boundary conditions. The system of equations was written in cylindrical coordinates. The numerical solution of the system allowed to investigate the drying process and to found the distributions of basic phases parameters in dryer. The mathematical model was verified by using of experimental data (maltodextrin water solution) in the pilot spray-drying. It was found the model is adequate to the experiment.
The mathematical model has been used to scale-up the spray-dryer for dry biomass production. The main dryer sizes were found by calculation. The energy analysis based on the dynamic coefficients of energy consumption had been done for this apparatus. It was showed that inlet energy is used in spray-drying more efficiency then in vacuum freeze-dryer.
Thus, the application of spray-drying for probiotics production allowed to intensify the process, to reduce the drying time and to organize continuous process.
See the full pdf manuscript of the abstract.
Presented Wednesday 19, 16:40 to 17:00, in session EPIC-1: Intensified Plants & Process Integration (IPPI).
