title: Strategies to improve the mechanical strength and water resistance of agar films for food packaging applications.
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.
authors.affiliation: REQUIMTE/LAQV, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. Electronic address: ana.sousa@ars.usda.gov.
authors.forename: Ana M M
authors.initials: AM
authors.lastname: Sousa
authors.affiliation: REQUIMTE/LAQV, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal. Electronic address: pilarg@fe.up.pt.
authors.forename: Maria P
authors.initials: MP
authors.lastname: Gonçalves
mesh_terms: D000362:Agar / Q000737:chemistry*; D004548:Elasticity; D018857:Food Packaging; D005685:Galactans / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D008351:Mannans / Q000737:chemistry*; D010539:Permeability; D053149:Plant Gums / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*; D013227:Steam / Q000032:analysis; D013718:Tensile Strength; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D005685:Galactans; D005782:Gels; D008351:Mannans; D053149:Plant Gums; D013227:Steam; D014867:Water; D000362:Agar; C017471:locust bean gum
keywords: Alkali-modified agar; Integrated multi-trophic aquaculture; Locust bean gum; Native agar; Packaging films; Synergisms