Interaction and phase behavior of whey protein and propylene glycol alginate complex condensates

• Published in: Food chemistry 2023-03, Vol.404 (Pt A), p.134556-134556, Article 134556
• Main Authors: Shi, Ge, Shi, Ce, Luo, Yongkang, Hong, Hui, Zhang, Jiaran, Li, Yan, Tan, Yuqing
• Format: Article
• Language: English
• Subjects: Alginates; Coacervate; Interaction; Molecular Docking Simulation; Phase behavior; Propylene glycol alginate; Whey protein; Whey Proteins
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2022.134556

[Display omitted] •PGA could reduce the pH of the maximum turbidity of WP solution.•PGA can improve the stability of WP at the isoelectric point.•The interaction between WP and PGA was the strongest at the ratio of 3:1.•WP and PGA formed soluble complexes at pH 4.6 and the WP/PGA ratio of 3:1.•WP/PGA = 3:1, pH 4.6 can be used as a new encapsulation wall material formula. WP: whey protein; PGA: propylene glycol alginate. Whey protein (WP) is ubiquitously applied in food products, but its sensitivity to food processing conditions has limited its application. Herein, we chose propylene glycol alginate (PGA) to combine with WP to enhance its stability. The ideal ratio of WP/PGA for coacervation was 3:1, and the soluble complex and insoluble complex were formed at pH 5.2 (pHc) and pH 4.4 (pHφ1) at this ratio, respectively. The UV absorption spectra, fluorescence spectra, and XRD results revealed that the interaction between PGA and WP changed the tertiary conformation of WP. The FTIR and molecular docking results suggested electrostatic interactions, hydrogen bonding and hydrophobic interactions were all involved in the formation of WP-PGA complexes, and the thermal stability of WP was improved based on the DSC results. These findings supported PGA to keep dairy products stable and transparent at the isoelectric point and WP-PGA complexes could be applied in encapsulating bioactive substances.