Comparison of drying methods for instant colostrum powder production: fluid bed dryer as post-drying approach

Colostrum is a valuable functional ingredient thanks to its rich composition of bioactive compounds, particularly immunoglobulins and growth factors, as well as its nutritional value. In addition to its use for calf nutrition and immune system support, colostrum is used to produce functional foods for human consumption. Various methods are available to prevent colostrum waste and to process it into various products. Traditional drying methods, such as spray and freeze drying, are widely used to extend shelf life. However, the resulting powders often exhibit poor instant drying properties, such as low dispersibility, solubility and wettability. Fluidized bed drying has emerged as a promising post-drying technology to address these limitations. This technique enables particle agglomeration and surface modification, increasing powder flowability, reducing cohesiveness and improving reconstitution behaviour in aqueous media. Furthermore, binders such as maltodextrin, lactose or sucrose during fluidized bed agglomeration can further stabilize the immunoglobulin content and reduce moisture uptake during storage. Optimizing process parameters such as inlet air temperature, binder concentration and fluidization air flow can yield colostrum powders with superior technological and functional properties. In this review, drying methods of colostrum powder are discussed comparatively and the potential of using the agglomeration process with a fluidized bed dryer to improve powder properties after drying is discussed. Consequently, fluidized bed drying represents a valuable strategy for developing instant colostrum powders, facilitating their application in various functional food matrices and increasing consumer acceptance.