Efficient process for the production of permeate powders
Résumé
An innovative process scheme for the production of permeate powders is evaluated in this paper. It is based on an overconcentration step that makes it possible to replace the spray-drying step used in conventional processes. This innovative processing scheme includes: (1) overconcentration of the permeate concentrate from 60 to 80% w/w dry matter (DM) content; (2) granulation of the overconcentrate with powder up to 88% DM; and (3) drying of the granules up to 97% DM. The feasibility of the process was validated at the pilot scale and the properties of the resulting permeate powder were comparable to those of a powder produced using the conventional process. Consideringwater removal, the energy savings in comparison to the conventional process were estimated in the range of 10.7 to 23.5%, and up to 32% when considering the whole production process or the drying step alone, respectively. Industrial relevance: The global demand ofwhey and permeate powders has considerably grownover the past decade, especially due to the increasing production of infant milk powders. The transformation of a liquid product into a powder requires a high energy-consuming drying step and energy savings on the current technology, i.e., spray drying, are difficult to achieve sincemost of the energy is used forwater removal. One solution is to develop a disruptive technology allowing the production of powders without spray drying, as proposed and described in this paper. The new process scheme is composed of three thin-film rotary evaporators in series, specifically designed to handle highly viscous products. The feasibility of the process was validated at the pilot scale and the results showed that it leads to significant savings on energy and building requirements for a quality of powder at least equivalent to a standard powder produced using conventional technologies.