For a fast protein consumption, many sport drinks contain a high concentration of whey protein. It can be mixed with water or milk at home or directly in the gym. The drying of food is a common method to improve food stability. Unfortunately, food quality suffers from this treatment, as flavor, aroma, appearance and nutrient value are decreased in dry products. Manufacturers are looking for drying treatments that are gentler with lower energy requirements. The method of the inert gas injection into the material is well known, as the drying rate is increased with the creation of a foamed structure. It results in a reduced drying time and an improved quality of the dried product due to less thermal degradation. Creating a stable foam is a major challenge for the food industry, the problem being solved by the use of emulsifiers, although they are not desired by the costumer. Additionally, foaming is often a very harsh treatment and not suitable for sensitive material such as flavors or proteins.
The Application Process, Working Conditions & Expected Outcomes
Conventional methods for the production of powders are spray drying or freeze drying. The process efficiency is directly proportional to the particle size. Larger particle sizes have to be compensated by higher atomization pressures, higher temperatures and larger spraying units for a longer residence time. A reduced bulk density can improve the process efficiency, as the heat transfer is faster. It depends on the amount of gas incorporated into the material, as a foamed structure creates a huger surface to volume ratio. The smaller the bubble, the greater the surface.
Therefore, small bubbles with high gas volume fractions are desired. With the new dynamically enhanced membrane foaming process, the current problems are solved. It is scientifically proven that the energy input is reduced compared to conventional available rotor-stator devices, as a reduced shear stress is required for smaller bubble sizes, ideal for sensitive material such as proteins. Additionally, the dynamically enhanced membrane foaming systems has the advantage to apply shear stresses decoupled from the through put, allowing constant process parameters. Gas fractions up to 83% with a 10 times larger surface can be reached, independent of the choice of gas. The dynamically enhanced membrane foaming device allows the production of a natural, stable, low density foam for an efficient drying process for sensitive material.
A dynamically enhanced membrane device consists in principle of a cylindrical working chamber in which a membrane is installed coaxially over a shaft. The working chamber has two product inlets, one for the dispersed (inner) phase and one for the continuous (outer) phase. The dispersed phase streams axially into the inside and will be dispersed into the continuous phase while flowing through the pores of the membrane. The drop detachment is additionally supported by the fast rotation of the inner cylinder. The drop formation or its size distribution depends on the process parameters: Speed, pore diameter of the membrane, viscosity of the continuous phase and the shear gap. The formed drops are detached continuously by the outer phase.
The dynamically enhanced membrane foaming systems has the advantage of being able to apply shear stresses decoupled from the throughput. The shear stress can be controlled by the rotational speed of the inner cylinder. The membrane itself is static, on which the inner surface bubbles are formed and detached from the wall. This new technology creates a new field of stable foams without the addition of any emulsifiers or stabilizers. It is a continuous process, with a low energy requirement, ideal for sensitive material like whey proteins. Kinematica, a swiss company with a long experience in the rotor/stator-technology, owns a patented solution called MEGATRON® MT-MM.
As a producer, you can benefit from different features this new technology offers:
- Natural and efficient drying
- Up to 10 times increased surface
- Constant and continuous foam production
- Choice of bulk density and gas freely selectable