Changes in the gel characteristics of two hen egg white powders modified by dry heating and the Maillard reaction during long-term storage

Abstract

Heating and the Maillard reaction applied at the dry state of dried hen egg white (DEW) powder represent two effective approaches for improving the functionality of DEW, especially the gelling properties. In this study, DEW modified by dry heating (DHEW) and the Maillard reaction with maltodextrin (MDEW) was stored at 25 ± 2 °C and 65 ± 3% relative humidity for 12 months to investigate the changes in gel characteristics. The results showed that the Tgel values of DEW, DHEW and MDEW increased to 71 ± 2 °C, 68 ± 1 °C and 66 ± 2 °C, respectively, after storage for 12 months. The gel hardness of the three samples decreased linearly with increasing storage time. Coarse and porous gels of different DEWs were observed after long-term storage. The storage-induced loss of gel properties of the three DEWs was responsible for the thermal characteristics. The storage stability of MDEW was better than that of DHEW during the entire storage period, although MDEW developed a brown colour more easily than DHEW after 6 months of storage. These results provide valuable information on different egg white powders under long-term ambient storage.