Fabrication and Characterization of Gluten Film Reinforced by Lycopene-Loaded Electrospun Polylactic Acid Nano-fibers

Abstract

Reinforced edible gluten film was successfully prepared by the addition of polylactic acid (PLA) nano-fibers to improve their mechanical and barrier properties. Scanning electron microscopy (SEM) of the transverse cross-section of gluten film was performed to investigate the binding of PLA fibers to the surface of gluten film. It was observed that the nano-fibers attached to the surface of the gluten film could improve by 13.9% in the barrier properties and up to 29.3% in the mechanical properties compared to the control gluten film. The effect of ultraviolet light exposure on the tensile strength and water vapor barrier properties, as well as the stability of lycopene encapsulated in PLA nano-fibers, was investigated. It was shown that PLA nano-fibers in gluten film reduce UV light’s harmful effect on the water vapor barrier properties by up to 6.8% and on the tensile strength up to 23.5% compared to the control film. The results also showed that the treatment of lycopene with ultraviolet light, unlike the control sample (55.7% degradation in lycopene), had no destructive effect on the antioxidant activity of lycopene. Finally, the rate of release of lycopene was studied in fatty food simulants. It was observed in gluten/PLA film that the encapsulation of lycopene in PLA nano-fibers has a much lower rate of release than the direct addition of lycopene to gluten film. Gluten film containing electrospun nano-fibers showed a release rate of lycopene about 31.8% at approximately 90 h. However, the sample of nano-fibers-free gluten film had a release rate of 48.5% at the same time. This result is beneficial for active food packaging because it allows food to be stored for longer in the packaging.