Dry-pasteurization of egg albumen powder in a fluidized bed. II. Effect on functional properties: gelation and foaming

Dry-pasteurization of egg albumen (EA) powder in a fluidized bed was studied in two experiments. Experiment 1 consisted of two different temperatures (90 and 130 °C) and experiment 2 of two air moisture levels (high and low). Powders were processed from 10 min to 3 h. The reference treatment was traditional pasteurization at 90 °C for 21 h. The fluidized bed treatment effects on gel texture, water-holding capacity (WHC), protein binding, gel colour, foaming capacity, foam stability and surface pressure were evaluated. Gels of EA powders treated at high temperature and high air moisture levels exhibited higher stress, strain and WHC values than gels of untreated EA powder. The gel colour became significantly darker, greener and less yellow by fluidized bed treatment. Foaming and surface activity properties were un-affected by the treatments, however, foam stability against liquid drainage correlated positively with surface pressure.