Physicochemical and functional characteristics of egg white powder as affected by pre-treatment and drying methods

Egg white is often regarded as a high-quality protein source that contains all essential amino acids required by humans. A fresh egg in liquid form has a short shelf life, thus
drying it into powder can be the best alternative for a longer short life. This research aimed to evaluate the physicochemical and functional characteristics of egg white powder (EWP) as affected by pasteurization as pre-treatment and drying methods. There were six treatments in the preparation of EWP, i.e., pasteurization, unpasteurization and combined with three drying methods (spray-, cabinet-, or freeze-drying). The physical and functional properties of EWP were determined i.e., the yield, color, water activity, bulk density, flowability, foaming, emulsification, water absorption (WAC), oil absorption capacity (OAC), and gel strength. The chemical properties i.e. moisture content, fat, ash, protein content, protein digestibility, and antioxidant activity were also determined. The results
showed that pasteurization and different drying methods affected the physicochemical and functionality of EWP. Pasteurization treatment significantly increased the bulk density of EWP prepared by spray- and cabinet drying, WAC of EWP prepared by spray- and cabinet drying, gel strength of EWP prepared by spray drying, the protein content of EWP
prepared by spray drying, protein digestibility of EWP prepared by spray- and cabinet drying; however, significantly decreased the aerated and tapped bulk density of EWP prepared by freeze-drying, gel strength of EWP prepared by cabinet- and freeze-drying, the protein content of EWP prepared by cabinet- and freeze-drying, protein digestibility of EWP prepared by freeze-drying, antioxidant activity of EWP prepared by spray-, cabinet-, and freeze-drying. Different drying methods significantly affected the color parameters, bulk density, gel strength, moisture content, protein content and protein digestibility. This
study suggested that the best characteristic of EWP was that of unpasteurized and prepared by freeze-drying method.