Development of a novel controlled-release nanocomposite based on poly(lactic acid) to increase the oxidative stability of soybean oil

Abstract

A poly(lactic acid) (PLA)-based nanocomposite active packaging was developed for the controlled release of tert-butylhydroquinone (TBHQ) antioxidant. The PLA-based active films were loaded with only TBHQ (3% wt) or a mixture of modified cellulose nanofibre (MCNF) (8% wt) and TBHQ (3% wt) to obtain active and nanocomposite active films, respectively. Release studies indicated that the release rate of TBHQ in 95% ethanol simulant was significantly decreased by the addition of MCNF. Moreover, the presence of MCNF diminished the increasing effect of temperature on the release rate as when storage temperature increased from 4°C to 40°C. The diffusion coefficient (D) for PLA-TBHQ and PLA-MCNF-TBHQ films increased from 6.75 and 4.34 × 10⁻⁸ cm² s⁻¹ to 19.85 and 8.49 × 10⁻⁸ cm² s⁻¹, respectively. Diffusion of TBHQ to soybean oil was enough to delay the induction of the oxidation of soybean oil stored for 6 months in contact with PLA-based films. Antioxidative activity of PLA-based active films considerably increased with increasing storage time as indicated by the increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the oxidative stability index (p < 0.05). This study demonstrates that effective controlled release antioxidant packaging could be obtained by using MCNF nanofiller, which leads to prolonged activity and an extended shelf-life in fatty foods.

Keywords:

• poly(lactic acid)
• nanocomposite active packaging
• modified cellulose nanofibre
• release rate
• soybean oil oxidation

Acknowledgements

The authors wish to express their gratitude to the University of Tabriz for financial support and Takdaneh Corporation, especially Dr Asadi, for technical assistance in this research.