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The effects of different pH levels and ionic strength in calcium on the stability and aeration characteristics of dairy emulsions were investigated in this study. The results revealed that the stability and aeration characteristics of the emulsion were enhanced as the pH value increased from 6.5 to 7.0 and were optimal within the pH of 6.8~7.0, while the concentration of free calcium ions (Ca2+) was 2.94~3.22 mM. With the pH subsequently fixed at 6.8 and 7.0, when the addition of CaCl2 was increased to 2.00 mM (free Ca2+ strength > 4.11 mM), stability and aeration characteristics reduced significantly, including the flocculation of fat globules, an increase in particle size, and a decrease in the zeta potential and viscosity of the O/W emulsion, all leading to an increase in interfacial protein mass and decreased overrun and foam firmness. Overall, the results indicated that pH changes and CaCl2 addition significantly influenced the stability and aeration characteristics of dairy emulsions, by influencing free Ca2+ strength, which is an important factor in determining the quality of dairy emulsions. [ABSTRACT FROM AUTHOR]

Polyglycerol esters (PGEs) are used as emulsifiers in recombined dairy cream (RDC) to improve product quality. In this study, the effects of four PGEs with different polymerization degrees and esterification on the particle size, viscosity, zeta potential, and microrheology of RDC emulsions were investigated, and the whipping time, overrun, serum loss, and firmness of the RDC emulsions were recorded. The results show that the addition of the PGEs reduced the particle size (from 2.75 μm to 1.48–1.73 μm) and increased the viscosity (from 41.92 cP to 73.50–100 cP) and stability (from 0.354 to 0.105–0.128), which were related to the change in interfacial properties and the weakening of Brownian motion, but there were differences in the effect on the whipping behavior of the RDCs. Although the addition of 0.9% triglyceride monolaurate gave the emulsion the best stability, the RDC had a longer whipping time (318 s) and a lower overrun (116.6%). Comparatively, the 0.7–0.9% concentrations of PGE55 and tripolycerol monostearate (TMS) provided RDC with good stability and aeration characteristics, allowing inflation within 100 s and expansion rates of up to 218.24% and 186.88%, respectively. In addition, the higher degree of polymerization of polyglyceryl-10 monstearate (PMS) did not work well at any concentration. These results contribute to understanding the mechanism of action of PGEs and improving the quality of RDC. [ABSTRACT FROM AUTHOR]

This study investigated the effects of emulsifiers (mono- and diglycerides, Tween 80, LACTEM, and sodium stearyl lactylate), both individually and in combinations, on the partial coalescence of fat globules and fat crystallization behavior, as well as their influence on the stability of aerated emulsions (36 wt% fat). The extent of partial coalescence, solid fat content (SFC), and melting/crystallization profile of bulk anhydrous milk fat (AMF) blends were examined. Furthermore, the interfacial tension, particle size distribution, apparent viscosity, and creaming rate of the quiescent emulsions were measured, while the aeration properties, rheology, and microstructure of aerated emulsions were analyzed. Lipophilic-emulsifier formulas accelerated fat crystallization and achieved higher foam firmness, whereas mono- and diglycerides had a significant positive effect on the crystallization behavior of bulk AMF blends compared to the minor impact on emulsification. Moreover, the highly viscous emulsions that were obtained by combining more hydrophilic emulsifiers could be attributed to more partial coalescence and smaller globule particle size, especially with the inclusion of Tween 80, which was very efficient at reducing interfacial tension. The four-blend emulsifier formula produced a lower emulsion creaming rate and higher aeration activity (overrun) and its foam displayed regularly-shaped air bubbles enveloped by a fat network consisting of well-distributed fat clusters. Overall, the results showed that the choice of emulsifiers played a crucial role in the physical stability of aerated emulsions. • Lipophilic-emulsifier formulas achieved higher foam firmness. • Mono- and diglycerides (MDG) had a positive effect on the fat crystallization compared to the minor impact on emulsification. • Combining more hydrophilic emulsifiers like Tween 80 promoted partial coalescence. • The four-blend emulsifier formula had lower emulsion creaming rate and higher overrun. • The different emulsifier formulas affected the texture of the final aerated emulsion in different ways. [ABSTRACT FROM AUTHOR]

[Display omitted] • BT/LA blends have changed the emulsion stability and aeration performance. • Different chemical compositions determined the compatibility of BT/LA blends. • Partial coalescence occurred as the LA ratio increased when the SFC < 35 %. • Larger and inhomogeneous β′ and β crystal mixtures appeared as BT ratio increased. • Higher foam firmness was achieved by BT/LA blends with higher BT ratios. This study aimed to find new strategies for enhancing the stability and texture properties of aerated emulsion by combining different animal fats with different ratios. Beef tallow (BT)/ lard (LA) were mixed at different ratios to prepare oil-in-water (O/W) emulsions, with and without aeration. The compatibility, crystallization behavior, stability, and rheology in both O/W and aerated emulsion systems prepared with BT/LA binary blends were further investigated. Larger and inhomogeneous β′ and β crystal mixtures appeared as the BT ratio increased. Monotectic or eutectic interaction was displayed according to different BT/LA ratios, solid fat content (SFC) and temperatures. O/W emulsion prepared with BT/LA binary showed higher apparent viscosity with larger fat globules distributed as the BT ratio increased. BT had higher SFC at any given temperature and the fat globule aggregation extent was higher. Partial coalescence occurred as the LA ratio increased when SFC < 35 %. Higher foam firmness of the aerated emulsion was achieved by BT/LA binary with higher BT ratios. As a result, combining BT and LA with different ratios achieved higher emulsion stability and foam properties. This study provides a novel insight into the application of different animal fats and the improvement of high-quality whippable products. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effect of emulsifier blends with different structures and lipophilic-hydrophilic balance (HLB) on the interfacial composition and crystallization behavior, as well as on the aeration properties of emulsions. The droplet size, physical stability, rheological properties, and partial aggregation rate of the quiescent emulsions were determined. Further, the interfacial protein content, interfacial tension, interfacial rheological properties, and thermodynamic properties were analyzed, and the aeration and texture of the foams were recorded. First, there was a significant difference in emulsion droplet size after compounding with glyceryl monostearate (GM) even though sucrose ester S-1570 (SE) and polysorbate 80 (TW) had the same HLB (p < 0.05), but sorbitan monooleate 80 (SP)-TW performed consistently with GM-TW, having the smallest particle size. Secondly, the addition of GM-SE changed the thermodynamic properties and significantly increased the crystallization temperature of fat (15.79 °C), but had no significant effect on the aeration process. In addition, although GM-SE resulted in emulsions with the lowest interfacial tension, the fat globule surface exhibited viscous behavior (E' < E″) and the worst physical stability of the emulsion, while triglycerol monostearate (TMS)-TW balanced the interfacial tension and strength giving good performance in both emulsion stability and aeration characteristics. In general, the design of compounding emulsifiers should pay more attention to the structural of the emulsifier. These results provide an interesting point of departure for further development of compounding emulsifiers for different needs. • Compounding emulsifiers are more effective than single emulsifiers in improving emulsion stability. • The performance of the compounding emulsifier is influenced by the structure of the components. • The presence of sucrose esters significantly altered the thermodynamic properties of the emulsions. • The aerating properties of emulsions are influenced by the interfacial behavior of the emulsifier. [ABSTRACT FROM AUTHOR]

This study investigated the effect of the interfacial behavior of emulsifiers with different hydrophilic-lipophilic balance (HLB 3.8–15) values on the quality of reconstituted dairy cream (RDC). The results showed that the size and viscosity of the emulsion decreased by 29.69% and 31.44%, respectively, at HLB 15, and the ζ-potential increased by 20.49% at HLB 12.2, while the instability index declined at HLB 9.4, followed by an increase. Furthermore, the interfacial protein content also decreased with the increase of HLB, while the interfacial tension decreased to a minimum at HLB 10.5 (0.77 mN/m) and then increased. Similarly, the interfacial viscoelasticity shifted at HLB 10, while the RDC overrun reached 165.05% at HLB 12.2. These results enhance the understanding of the HLB impact on the interfacial behavior of emulsifiers and the relationship with RDC quality while providing guidance for selecting and developing compound emulsifiers for aerated emulsions. • The hydrophilic-lipophilic balances of emulsifier affects the aerated emulsion. • The emulsifier with HLB 9.4 provides optimal physical stability of the emulsion. • The interfacial rheological properties change from elastic to viscous at HLB 10. • Changes in interfacial behavior induced by HLB differences affect the emulsion aeration process. [ABSTRACT FROM AUTHOR]