Characterization of ultrasound-induced soybean peptide particles (SPPs) and SPP-stabilized Pickering emulsions combined with amino acid sequence analysis

• Published in: Food hydrocolloids 2025-06, Vol.163, p.111073, Article 111073
• Main Authors: Han, Ping, Zhao, Mou, Wang, Zhouping, Chen, Nengmao, Liu, Fuguo, Lu, Shiling, Dong, Juan, Sun, Jingtao
• Format: Article
• Language: English
• Subjects: Amino acid sequence; Antioxidant capacity; Soybean peptide particles; Stable pickering emulsion; Ultrasonic treatment
• ISSN: 0268-005X
• DOI: 10.1016/j.foodhyd.2025.111073

To expand the application of insoluble soybean peptide aggregates in food products, this study focused on soybean peptide particles (SPPs) prepared via different ultrasonic treatments to optimize ultrasonic parameters. The results demonstrated that ultrasound can transform the β-sheets of SPPs into β-turns. Unlike soybean protein isolate particles, which are spherical, the SPPs were flaky. Moreover, as ultrasonication was prolonged and the ultrasonic power was increased, more uniform and smaller SPPs were generated. Accordingly, the particle size and absolute value of the ζ-potential decreased, while the surface hydrophobicity increased. SPP-7 (450 W, 20 min) exhibited neutral wettability (θ = 91.85° ± 2.21) and was effectively adsorbed and rearranged at the oil–water interface. Furthermore, SPP-7 exhibited the highest DPPH (45.66% ± 0.82%) and ABTS scavenging activity (41.63% ± 2.75%). The Pickering emulsion stabilized by SPP-7 (φ = 60%) possessed a dense structure and demonstrated superior storage stability. Liquid chromatography combined with tandem mass spectrometry showed that ultrasound treatment can increase the quantity of low-molecular-weight peptides in SPPs and decrease the average molecular weight of peptide segments. The N-terminal and C-terminal regions of these peptides were dominated by hydrophobic amino acids, and the ratio of acidic to basic amino acids was low, consistent with the results of wettability and surface hydrophobicity analysis. The improved properties of SPP-7 could be attributed to its unique peptide composition and the higher proportion of acidic (D, E) and hydrophobic amino acids (L, F, P, A) in these peptides. [Display omitted] •A series of soybean peptide particles (SPPs) were obtained through ultrasonic.•Ultrasonic treatment improved the H0 and decreased the size of SPPs.•Neutral wettability and excellent O/W interface of SPP-7 formed stable emulsion.•Average MW of peptides decreased and low molecular peptides increased by ultrasound.•Unique peptide of SPP-7 had more hydrophobic amino acids and acidic amino acids.