A tuning molecular conformation strategy of interfacial glycosylated cod proteins enables high internal phase emulsions with freeze-thaw stability

Abstract

Sugar is known to be used as a protective agent for protein function during lyophilization. However, it has not been reported that sugar changes protein structure during lyophilization process, thus improving protein functional properties. In this study, the freeze-thaw stable high internal phase emulsions (HIPEs) could be prepared by the glycosylated cod protein lyophilized with glucose, but not the glycosylated cod protein which was lyophilized before adding glucose. The results showed that β-turn content of the protein lyophilized with glucose disappeared while β-sheet increased sharply (from 34.0 ± 2.4 to 41.2 ± 1.8) at the sublimation stage in the lyophilization. This might be one of the key factors for preparing freeze-thaw stable HIPEs because it was easier for protein to form stable layers around the oil droplets to against the oil or ice crystals. The obtained results are expected to change the role of lyophilization in the field of protein application, enabling the development of new materials.