LAUSR

Vitamins and flavonoids are two kinds of essential trace bioactives which are prone to photodegradation during food processing and storage. In this study, a particle stabilized water-in-water (W/W) emulsion system composed of soy protein isolate (SPI) and guar gum (GG) was applied in loading riboflavin. Based on the significant binding affinity differences of SPI (Ka = 1.11 × 105 L mol-1) and GG (Ka = 9.00 × 103 L mol-1) to riboflavin, this hydrophilic and light-sensitive bioactive compound was loaded in SPI-rich droplets. Confocal images indicated that a stable microstructure of SPI-rich droplets suspended in GG-rich continuous phase was successfully constructed through manipulating the proportion of the two polymeric components and using zein-based particles (ZPs) as stabilizers. These negatively charged particles modified by pectin with a hydrodynamic diameter of 533 ± 5.7 nm were able to adsorb at the SPI/GG interface, and subsequently stabilized the SPI-in-GG emulsion. Fluorescence spectra of riboflavin suggested that the formation of such W/W emulsion could effectively delay the photodegradation of riboflavin during an 8 h ultraviolet (UV) irradiation. And its color was maintained to a maximum extent. Therefore, this structured W/W emulsion could be a desired architecture for delivering light-sensitive cargo.