The physicochemical properties of peanut protein‐stabilized emulsions and emulsion gels prepared by high‐intensity ultrasound (HIU) and high‐pressure homogenization (HPH) were compared. The effects of different ultrasound emulsification conditions (ultrasonic time and power, protein concentration, and oil phase percentage) on the initial particle size and stability of peanut protein‐stabilized emulsions were investigated. It was observed that the optimal HIU emulsification conditions consisted of a concentration of 4% (w/v) proteins, a volume percentage of 30% (v/v) oil, and an ultrasonic treatment at 300 W for 20 min. Compared with the two emulsions prepared by HPH at 300 and 500 bar, respectively, the HIU‐prepared fresh emulsion showed a larger particle size, similar zeta potential but higher interfacial protein concentration and apparent viscosity. Additionally, the HIU‐prepared emulsion had lower flocculation and coalescence indices and was more resistant to gravitation separation during storage. The cold‐set gel strength of the HIU‐prepared emulsion was stronger than that of the HPH‐prepared emulsion (300 bar), but weaker than that of the emulsion (500 bar). The non‐adsorbed proteins from the HIU‐prepared emulsion had unique structural characteristics, such as higher molecular weight, more unordered secondary structures, and stronger surface hydrophobicity, which likely explained why the HIU‐prepared emulsion possessed better physical stability and gelling ability.Practical ApplicationsHigh‐pressure homogenization (HPH) is currently the most frequently used method in the food industry to produce emulsions. However, a high‐pressure homogenizer is expensive and not easy to operate. In contrast, high‐intensity ultrasound (HIU) emulsification is considered a cost‐effective technique. In this study, a peanut protein‐stabilized emulsion was successfully produced by HIU emulsification method. Its physical stability was significantly better than that of the emulsions made by HPH. This work provides new knowledge for the application of peanut protein as a natural emulsifier combined with ultrasonic technology in the food industry.

Emulsions of peanut and soy proteins, including their major components (arachin, conarachin, glycinin and β−conglycinin), were prepared by ultrasonication (300 W, 20 min) at a constant protein concentration (4%, w/v) and oil fraction (30%, v/v). These emulsions were then induced by CaCl2, transglutaminase (TGase) and glucono-δ-lactone (GDL) to form emulsion gels. The optimum coagulant concentrations were obtained for peanut and soy protein-stabilized emulsion gels, such as CaCl2 (0.15 and 0.25 g/dL, respectively), TGase (25 U/mL) and GDL (0.3% and 0.5%, w/v, respectively). For the CaCl2-induced emulsion gels, the hardness of the β−conglycinin gel was the highest, whereas that of the conarachin gel was the lowest. However, when TGase and GDL were used as coagulants, the strength of the conarachin emulsion gel was the best. For the GDL-induced emulsion gels, microstructural analysis indicated that the conarachin gel showed more homogeneous and compact structures. The gelation kinetics showed that the storage modulus (G’) of all the GDL-induced emulsions increased sharply except for the arachin-stabilized emulsion. The interactive force nature varied between conarachin and arachin emulsion gels. This work reveals that peanut conarachin could be used as a good protein source to produce emulsion gels when suitable coagulants are selected.