Air-water interfacial adsorption mechanism of whey protein/β-glucan complexes induced by phase behavior: Development of an emerging foaming agent

• Published in: Food hydrocolloids Vol. 167; p. 111408
• Main Authors: Hu, Jialun, Xu, Heyang, Jiang, Zhanmei, Hou, Juncai
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2025
• Subjects: adsorption; Air-water interfacial adsorption; Foam characteristics; foams; hydrocolloids; liquid-air interface; Oat β-glucan; oats; Phase region; whey; whey protein; Whey protein isolation; Oat β-glucan; Air-water interfacial adsorption; Whey protein isolation; Foam characteristics; Phase region
• ISSN: 0268-005X
• DOI: 10.1016/j.foodhyd.2025.111408

In this study, whey protein isolation (WPI) and oat β-glucan (Glu) were selected as the primary subjects of investigation. The research focused on the pH-induced phase behavior of the WPI/Glu complex, examining the relationship between adsorption behavior, foaming properties, and the air-water interface across distinct phase regions and characteristic phase domains. The analysis was conducted at both microscopic and macroscopic levels to elucidate the underlying mechanisms and interactions. In the process of WPI/Glu phase behavior, there are four characteristic phase regions, co-soluble region (pH 2.5, pH 7.0), soluble complex region (pH 5.5) and insoluble complex region (pH 4.5), namely. The trends in foaming ability and foam stability across different phase regions were as follows: soluble complex region (pH 5.5-WPI/Glu) > insoluble complex region (pH 4.5-WPI/Glu) > co-soluble region (pH 7.0-WPI/Glu) > co-soluble region (pH 2.5-WPI/Glu). Compared to the co-soluble complex at pH 2.5, the soluble complex demonstrated a 90.1 % improvement in foaming ability and an 80.9 % improvement in foam stability. Additionally, the soluble complex (pH 5.5-WPI/Glu) reduced air-water interface tension, exhibited high adsorption quality, and formed a dense, rigid interface layer. These findings confirm that foaming ability and foam stability are positively correlated with interfacial adsorption capacity. Moreover, the WPI/Glu complexes prepared in the soluble complex region exhibited superior foam characteristics. [Display omitted] •In WPI-Glu phase behavior, the soluble phase region has the best foam characteristics.•A large number of soluble complexes can be quickly adsorbed on the air-water interface.•The interfacial film formed by soluble complexes has the best viscoelasticity to resist warp.•Visualization of foam microscope by computer simulation, and the foam conforms to Plateau's law.