Effects of freezing and drying programs on IgY aggregation and activity during microwave freeze-drying: Protective effects and interactions of trehalose and mannitol

The acquisition of high quality lyophilized IgY products, characterized by an aesthetically pleasing visage, heightened stability, and a marked preservation of activity, constitutes an indispensable pursuit in augmenting the safety and pragmatic utility of IgY. Within this context, an exploration was undertaken to investigate an innovative modality encompassing microwave freeze-drying (MFD) as a preparatory methodology of IgY. Morphological assessments revealed that both cryogenic freezing and subsequent MFD procedures resulted in aggregation of IgY, with the deleterious influence posed by the MFD phase transcending that of the freezing phase. The composite protective agent comprised of trehalose and mannitol engendered a safeguarding effect on the structural integrity of IgY, thereby attenuating reducing aggregation between IgY during the freeze-drying process. Enzyme-linked immunosorbent assay (ELISA) outcomes demonstrated a discernible correlation between IgY aggregation and a notable reduction in its binding affinity towards the pertinent antigen. Comparative analysis vis-à-vis the control sample delineated that when the trehalose-to-mannitol ratio was upheld at 1:3, a two-fold outcome was achieved: a mitigation of the collapse susceptibility within the final product as well as a deterrence of IgY agglomeration, concomitant with an elevated preservation rate of active antibodies (78.57 %).