Modification of Soybean Protein Isolate by Cold Plasma Treatment and Improvement of Its Interface Properties
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
As a plant-sourced protein, soy protein isolate (SPI) is widely used in food. However, interface properties of SPI are poor, which affects its application in emulsion food. In this study, SPI is treated with cold plasma to investigate the changes in its structure and improvement of its interface properties. The results showed that the α-helix contents of SPI decreased from 31.93% to 23.56% after treatment with cold plasma for 60 s, and its tertiary conformations changed to a more compact structure. The emulsifying properties of SPI, including the surface properties, water-holding capacity (WHC), and fat-holding capacity (FHC), were also improved significantly. The particle size distribution of the cold plasma-treated protein solutions gradually narrowed, and the absolute value of ζ-potential also changed. Moreover, free sulfhydryl content increased from 9.77 μmol/g protein (untreated SPI) to 17.76 μmol/g protein (50 W, 60 s) with the increase in cold-plasma treatment duration. The surface hydrophobicity of SPI dispersions increased from 2,330.9 to 3,680.7 after treatment with cold plasma. The microstructures of SPI treated with cold plasma exhibited a more uniform aggregation. Conclusively, this study showed that cold plasma treatment could modify the protein structure and physical properties of SPI and enhance its interface properties, which could expand the application of SPI in food. Key words:
