Antimicrobial edible materials via nano-modifications for food safety applications

Edible films from carboxymethyl cellulose (CMC)/starch incorporated with titanium dioxide (TiO2) nanoparticles were developed. The prepared films were characterized by Fourier transforms infrared, X-ray diffraction, transmission electron microscopy, dynamic light scattering, swelling behaviour, and thermal and mechanical properties. Results showed a decrease in the average particle size of TiO2 nanoparticles with increasing irradiation dose up to 30 kGy. The swelling capacity of CMC/starch blends is ordered in the sequence of composition ratio 2:1 > 1:1 > 1:2. The effect of different irradiation doses (2.5, 5, 10, 15, and 20 kGy) and different concentrations of TiO2 (0.5, 1, 1.5, 2, 2.5, and 3 wt%) on the film properties was evaluated. The tensile strength increased gradually, accompanied by a decline in elongation percentage with the increase in the irradiation dose and increase in the TiO2 contents up to 2.5 wt%. The irradiated CMC/starch/TiO2 film showed higher thermal stability than CMC/starch film. Furthermore, the unirradiated and irradiated CMC/starch/TiO2 edible films were applied to fresh strawberries by surface coating. The irradiated film showed a superior effect in prolonging the fruits' shelf life. The antimicrobial activity of CMC/starch/TiO2 film against Escherichia coli and Staphylococcus aureus was increased by increasing the irradiation dose. In conclusion, CMC/starch/TiO2 edible film exhibited the prerequisite behaviour for potential application in active food packaging.

Automated summary

Edible films made from carboxymethyl cellulose (CMC)/starch incorporated with titanium dioxide (TiO2) nanoparticles were developed and characterized in terms of various properties. The results showed that the irradiation dose and TiO2 content affected the thermal stability, mechanical properties, and antimicrobial activity of the films. The irradiated CMC/starch/TiO2 film demonstrated prolonged shelf life for strawberries. These edible films have the potential for application in active food packaging.