pH-sensitive soluble soybean polysaccharide/SiO₂ incorporated with curcumin for intelligent packaging applications

In the present work, the effect of various concentrations of SiO₂ nanoparticles (5, 10, and 15%) on physicochemical and antimicrobial properties of soluble soybean polysaccharide (SSPS)-based film was investigated. Then, the migration of SiO₂ nanoparticles to ethanol as a food simulant was evaluated. Subsequently, curcumin was added to the nanocomposite formulation to sense the pH changes. Finally, the cytotoxicity of the developed packaging system was investigated. With increasing nanoparticle concentration, the film thickness, water solubility, and water vapor permeability decreased and mechanical performance of the films improved. SSPS/SiO₂ nanocomposite did not show antibacterial activity. SEM analysis showed that SiO₂ nanoparticles are uniformly distributed in the SSPS matrix; however, some outstanding spots can be observed in the matrix. A very homogeneous surface was observed for neat SSPS film with R _a and R _q values of 3.48 and 4.26, respectively. With the incorporation of SiO₂ (15%) into SSPS film, R _a and R _q values increased to 5.67 and 5.98, respectively. Small amount of SiO₂ nanoparticles was released in food simulant. The nanocomposite incorporated with curcumin showed good physical properties and antibacterial activity. A strong positive correlation was observed between TVBN content of shrimp and a* values of the films during storage time (Pearson's correlation = 0.985).