Effect of the incorporation of lignin microparticles on the properties of the thermoplastic starch/pectin blend obtained by extrusion

Int J Biol Macromol. 2021 Jun 1:180:262-271. doi: 10.1016/j.ijbiomac.2021.03.076. Epub 2021 Mar 15.

Abstract

The present study aimed to produce thermoplastic starch films with different concentrations of thermoplastic pectin and the addition of 4% lignin microparticles as a reinforcing and active agent. The pectin improved the modulus of elasticity, and decreased the elongation at break. In addition, it improved the UV light protection to 100% at 320 nm and 95.9% at 400 nm. The incorporation of lignin microparticles improved the thermal stability of the blends made with 25% and 50% thermoplastic pectin when compared to the pectin-free blends. The blend with 25% thermoplastic pectin led to an increase of 75.8% and 34% in elongation at break and deformation of the films, respectively. This blend also improved the UV light protection to 100% due to its dark brown color. Regarding the permeability properties, the films with 25% and 50% thermoplastic pectin showed lower oxygen permeability (48% and 65%) and an increase in the antioxidant activities from 2.7% to 71.08% and 4.1% to 79.28%, respectively. Thus, the polymer blend with 25% thermoplastic pectin with the incorporation of lignin microparticles proved to be a good alternative for use in foods sensitive to the effects of oxygen and UV light.

Keywords: Antioxidant; Biodegradable; Extrusion.

MeSH terms

  • Antioxidants / chemistry*
  • Biodegradable Plastics / chemistry*
  • Color
  • Elasticity
  • Food Industry
  • Lignin / chemistry*
  • Microplastics / chemistry*
  • Oxygen / chemistry
  • Pectins / chemistry*
  • Pectins / radiation effects
  • Permeability
  • Solubility
  • Starch / chemistry*
  • Steam
  • Ultraviolet Rays
  • Water / chemistry

Substances

  • Antioxidants
  • Biodegradable Plastics
  • Microplastics
  • Steam
  • Water
  • Pectins
  • Starch
  • Lignin
  • Oxygen