Effects of high pressure processing on structure and emulsifying properties of lactoferrin-xanthan gum complex

Abstract

The influence of high pressure processing (HPP) and polysaccharides on the structure and emulsifying properties of lactoferrin (LF) has been investigated by fluorescence, circular dichroism, FTIR, dynamic light scattering, physical stability, confocal laser scanning microscopy, and microrheology measurements. Compared with LF alone, the presence of xanthan gum (XG) inhibited the exposure of hydrophobic core in LF caused by HPP to a certain extent. HPP slightly changed the secondary structure of LF, while the addition of XG expanded the effect. 200 MPa treatment was favorable for LF-XG complexes to form ordered structure, while higher pressure decreased the content of α-helix. HPP treatment or XG addition both led LF molecules to unfold, while the combination of them caused LF to fold under certain conditions. Droplet sizes of LF-XG stabilized emulsions were smallest under 400 MPa. HPP increased the charges on the surface of droplets. HPP caused the oil droplets closer to spherical, more evenly distributed and reduced the flocculation among droplets. The Addition of 0.3 wt% XG or combination of 0.2 wt% XG and HPP could maximize the physical stability of emulsions. By altering the molecular structure of LF or LF-XG, HPP, and XG increased the viscoelasticity of emulsions.

GRAPHICAL ABSTRACT

Keywords:

• High pressure processing
• lactoferrin
• xanthan gum
• structure
• emulsifying properties

Author contributions

Conceptualization: Fang Yuan & Xiaoye He; Methodology: Xiaoye He; Formal analysis and investigation: Xiaoye He & Shuang Ren; Writing - original draft preparation: Xiaoye He & Shuang Ren; Writing - review and editing: Xiaoye He, Shuang Ren, & Jiaqi Su; Funding acquisition: Fang Yuan & Jing Wang; Resources: Fang Yuan & Jing Wang; Supervision: Fang Yuan & Jing Wang.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.

Data availability statement

All data generated or analyzed during this study are included in this published article.

Additional information

Funding

The research was funded by the Innovation Engineering Project of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2022-IFND).