Strategies to improve the mechanical strength and water resistance of agar films for food packaging applications

Carbohydr Polym. 2015 Nov 5:132:196-204. doi: 10.1016/j.carbpol.2015.06.022. Epub 2015 Jun 14.

Abstract

Agar films possess several properties adequate for food packaging applications. However, their high cost-production and quality variations caused by physiological and environmental factors affecting wild seaweeds make them less attractive for industries. In this work, native (NA) and alkali-modified (AA) agars obtained from sustainably grown seaweeds (integrated multi-trophic aquaculture) were mixed with locust bean gum (LBG) to make 'knife-coated' films with fixed final concentration (1 wt%) and variable agar/LBG ratios. Agar films were easier to process upon LBG addition (viscosity increase and gelling character decrease of the film-forming solutions observed by dynamic oscillatory and steady shear measurements). The mechanical properties and water resistance were optimal for films with 50 and/or 75% LBG contents and best in the case of NA (cheaper to extract). These findings can help reduce the cost-production of agar packaging films. Moreover, the controlled cultivation of seaweeds can provide continuous and reliable feedstock for transformation industries.

Keywords: Alkali-modified agar; Integrated multi-trophic aquaculture; Locust bean gum; Native agar; Packaging films; Synergisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agar / chemistry*
  • Elasticity
  • Food Packaging*
  • Galactans / chemistry*
  • Gels / chemistry
  • Mannans / chemistry*
  • Permeability
  • Plant Gums / chemistry*
  • Seaweed / chemistry*
  • Steam / analysis
  • Tensile Strength
  • Viscosity
  • Water / chemistry

Substances

  • Galactans
  • Gels
  • Mannans
  • Plant Gums
  • Steam
  • Water
  • Agar
  • locust bean gum