Interfacial properties of camel milk and their influence on microfoam stability

The interfacial performance of camel milk at the air-water interface and their influence on microfoam rheology were investigated. Interfacial properties were quantified using dilatational rheology coupled with modelling, and foam characteristics were probed using a dynamic foam analyser combined with rheological analysis. Lissajous curve and intracycle moduli analyses were employed to examine the viscoelastic properties of films. Microfoam characteristics were assessed in samples prepared by steam injection. Ward-Tordai and Graham-Phillips models revealed that camel milk proteins diffuse (0.399 mN/m s -0.5 ) and adsorb (0.0026 s -1 ) faster than those from bovine milk. Additionally, strain hardening behaviour at expansion supported a lower bubble growth rate (∼4.24 μm 2 /s) and higher foam viscosity (∼4000 Pa.s) in camel milk than in bovine milk. Camel milk microfoams exhibited lower viscosity (142 mPa.s) than those made with bovine milk (186 mPa.s) beyond the critical stress. No milk proteins exhibited selective adsorption at the interface; instead, the mechanical properties of the films controlled bubble stability and foam rheology. Overall, camel milk microfoams exhibited superior interfacial stability, indicating that camel milk is a viable alternative to bovine milk in foaming applications. • Camel milk (CM) presents desirable mechanical properties for microfoams • CM exhibits faster diffusion and adsorption kinetics at the air-water interface • CM presents a remarkable non-linear response at the air-water interface • Milk proteins do not show selective adsorption at the air-water interface • β -Lg may form weaker films than α -La at the air-water interface