Construction and regulation of thermal-induced yeast protein gels: Effects of Succinylation degree on gelation behavior and underlying mechanism.

The non-gelling property of yeast proteins (YP), a promising alternative protein source, highly limited its extensive application in gel-based products. Herein, we reported a strategy for the construction and regulation of thermal-induced yeast protein gels through succinylation-ultrasound modification and succinylation degree modulation. Compared to the untreated YP, succinylation-ultrasound modification endows YP with thermal-induced gelling behavior, with a higher degree of succinylation performing better. As the succinylation degree increases, the texture profiles, transparency, and water-holding capacity exhibit obvious increasing trends. Moreover, microstructure observation revealed that a higher succinylation degree facilitates the generation of more regular network structures. Hydrophobic interactions and disulfide bonds are the dominant interactions in maintaining the gel network. With the succinylation degree increased, those dominated forces can be further enhanced, thus showing a better gelling properties. Multiple analyses demonstrated that the underlying mechanism for acquiring gelling properties of yeast protein is that succinylation-ultrasound treatment promotes the dissociation and unfolding of YP molecules, exposing more sulfhydryl groups and grafting multiple succinyl groups. A higher degree of succinylation shows better performance, which is beneficial for YP gelation during thermal processing. The findings provide an effective strategy for modulating the gelling property of yeast protein, and hold great potential for facilitating its application in the development of gel-based products.