Nanocomplexation of soy protein isolate with curcumin: Influence of ultrasonic treatment

• Published in: Food research international 2015-09, Vol.75, p.157-165
• Main Authors: Chen, Fei-Ping, Li, Bian-Shen, Tang, Chuan-He
• Format: Article
• Language: English
• Subjects: Complexation; Curcumin; Degradation stability; Foods; Formations; Hydrophobicity; Nano vehicle; Nanocomplexation; Nanostructure; Proteins; Soy protein isolate (SPI); Storage stability; Ultrasonic treatment; Ultrasonication
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2015.06.009

Soy protein isolate (SPI) can act as effective nanocarriers for water-insoluble curcumin, however, the maximal capacity of this protein to load curcumin and molecular mechanism for the formation of the nanocomplexes are still little known. This work investigated the formation and properties of SPI-curcumin nanocomplexes formed at a low concentration of 0.05% (w/v), as well as the influence of a high intensity ultrasonic treatment on the nanocomplexation. Most of the particles in non- or ultrasonic-treated SPIs were present in nanoparticle form with z-average sizes of about 50–52nm. The load amount (LA) of curcumin in the non-treated nanocomplexes reached 103.9μg/mg SPI. The ultrasonic treatment of the protein solution further significantly increased the LA, while the LA was considerably decreased by the treatment after the nanocomplexation. The complexation with curcumin significantly increased the particle size and ζ-potential of both non- and ultrasonic-treated SPIs, but led to a considerable reduction in surface hydrophobicity, with the greater changes observed for ultrasonic-treated SPI. The nanocomplexation with SPIs remarkably improved the storage stability of curcumin, with much better improvement observed for the ultrasonic-treated SPI. Both the number and nature of hydrophobic sites are important for the nanoparticles in SPI to exhibit high capacity to load curcumin molecules. This study confirmed that SPI exhibited a high capacity to load water-insoluble curcumin, and an ultrasonic pretreatment could further improve its encapsulation efficiency and stability of curcumin. •Soy protein isolate (SPI) exhibited a high capacity to bind curcumin.•Ultrasonication pretreatment significantly increased the curcumin load of SPI.•Ultrasonication treatment on the nanocomplexes remarkably decreased the curcumin load.•The nanocomplexation considerably increased the storage stability of curcumin.•The structural characteristics of SPI nanoparticles play a vital role in the nanocomplexation.