Comparison of drying techniques for bovine lactoferrin: Iron binding and antimicrobial properties of dried lactoferrin

ABSTRACT The effects of pilot scale freeze- and spray-drying on some functional properties of lactoferrin were studied. Denaturation and loss of function relative to the fresh concentrate as received from a dairy factory was estimated in three ways: (a) from the enthalpy of the denaturation peak; (b) by iron binding capacity as measured by atomic absorption spectroscopy before and after incubation with an iron-rich solution; and (c) from anti-microbial properties by incubation of multiple dilutions against three microorganisms for 48 h at 37 °C. Spray-dried lactoferrin showed significantly larger extent of denaturation, and lower iron binding capacity, when compared with fresh or freeze-dried lactoferrin. For all treatments, lactoferrin exhibited bacteriostatic activity even at low lactoferrin concentrations of 0.01 mg mL-1. No bactericidal activity was observed for any concentration or treatment of lactoferrin.