title: Interfacial and emulsifying properties of soybean peptides with different degrees of hydrolysis.
abstract: In this study, the effects of the degree of hydrolysis on the interfacial and emulsifying properties of soybean peptides were evaluated based on surface and interfacial tension, dynamic light scattering (DLS), and freeze-fracture transmission electron microscopy (FF-TEM) analyses. Of the five evaluated soybean peptides (SP95, SP87, SP75, SP49, and SP23), those with higher degrees of hydrolysis (SP95 and SP87) did not exhibit noticeable surface-active properties in water, whereas those with relatively low degrees of hydrolysis (SP75, SP49, and SP23) exhibited remarkable surface tension-lowering activity. The latter set (SP75, SP49, and SP23) also formed giant associates with average sizes ranging from 64.5 nm to 82.6 nm above their critical association concentration (CAC). Moreover, SP23 with the lowest degree of hydrolysis exhibited excellent emulsifying activity for soybean oil, and FF-TEM analysis demonstrated that the emulsions were stabilized by a lamella-like multilayer peptide structure on the oil droplets that prevented coagulation. The peptide with the lowest degree of hydrolysis (SP23) was effective not only for soybean oil emulsification, but also for the emulsification of liquid paraffin and silicon oil that are generally difficult to emulsify.
authors.affiliation: Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST).
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Mio
authors.initials: M
authors.lastname: Nakayama
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Taira
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abe
authors.forename: Dai
authors.initials: D
authors.lastname: Kitamoto
mesh_terms: D045703:Emulsifying Agents; D004655:Emulsions; D005614:Freeze Fracturing; D006868:Hydrolysis; D008027:Light; D008855:Microscopy, Electron, Scanning; D008899:Mineral Oil; D010316:Particle Size; D010455:Peptides / Q000737:chemistry*; D010940:Plant Proteins / Q000737:chemistry* / Q000648:ultrastructure; D012542:Scattering, Radiation; D013024:Soybean Oil; D013025:Glycine max / Q000737:chemistry*; D013500:Surface Tension; D013501:Surface-Active Agents
chemical_list: D045703:Emulsifying Agents; D004655:Emulsions; D010455:Peptides; D010940:Plant Proteins; D013501:Surface-Active Agents; D013024:Soybean Oil; D008899:Mineral Oil