In vitro evaluation of spray and freeze-dried bovine colostrum powder and their effects on the nutritional and functional properties

Bovine colostrum is the initial milk produced after birth that contains high levels of immunoglobulins and antimicrobial peptides. This study examined the production of bovine colostrum powder using two methods including spray- and freeze-drying. Spray-drying involves quickly drying a liquid or slurry with hot gas, while freeze-drying is a low-temperature dehydration process that preserves the product by freezing it and at reduced pressure. The aim was to compare the effectiveness of spray-drying versus freeze-drying in producing colostrum powder, focusing on protein and defensive protein content. The freeze-drying sample contained higher levels of protein and defensive proteins (IgG and IgA) compared to spray-drying. The DPPH value was high in freeze-dried samples, while higher values of FRAP, TPC, and ABTS were found in spray-dried samples. Microbiological analysis indicated freeze drying generally yielding lower counts. Sensory evaluation suggested that spray-dried colostrum scored higher for flavor and aroma, while freeze-dried samples were preferred in appearance. Overall, the study underscored the distinction between spray=drying and freeze-drying in producing bovine colostrum powder, with implications for nutritional content and sensory attributes.