Abstract:In this manuscript,the apparent density,color,and functional characteritics(gelling, foaming and emulsifying) were used to evaluate the quality of fresh duck egg white(FDEW) dried with conventional freeze-drying(CFD) and a pulse-spouted bed microwave freeze-drying(PSMFD),and desalted duck egg white(DDEW) with and without ultrasound pretreatments dried by FDEW and PSMFD. With fresh duck eggs as a control group. The results demonstrated that PSMFD yields dried DEW with a better color of higher L* and lower b* values as well as lower apparent density compared to FD. Apart from that,dried DEW with PSMFD can form a more transparent gelatin,higher foaming stability(FS) and emulsifying activity index(EAI) in comparison with CFD. After PSMFD,except for lower color difference and apparent density values,ultrasound pretreatment can produce the dried DDEW with higher gel hardness(831.251 g),higher foaming capacity(FC(86.7%)) and FS(93.3%),and higher emulsifying stability(ES(26.48 min)) relative to those obtained without ultrasound pretreatment.
