Effects of suppressing protein structural changes on the excellent gelling properties of dried egg white via dry-heat treatment
Shota Koyama, Yuko Nemoto, Masahiro Ichikawa, Daiki Oka, Yoshimasa Tsujii, Tomohiro Noguchi, Katsumi Takano, Akihiro Handa
Abstract
In this study, we analyzed the molecular properties and thermal behavior of dried egg white (DEW) proteins to understand the mechanisms underlying DEW gel hardening via dry-heat treatment. Dry-heat-treated DEW proteins displayed a higher surface negative charge and more isopeptide bonds, such as those in lanthionine and lysinoalanine. In addition, secondary structure and surface hydrophobicity measurements suggested that structural changes that occur during heating in solution were suppressed in dry-heat-treated DEW. The size of the protein aggregates did not change during heating in the diluted solution, and was almost the same as that of the gel structure unit.